diff --git a/apps/frontend/app/[locale]/dashboard/admin/organizations/page.tsx b/apps/frontend/app/[locale]/dashboard/admin/organizations/page.tsx
index 0773b97..84ecdd5 100644
--- a/apps/frontend/app/[locale]/dashboard/admin/organizations/page.tsx
+++ b/apps/frontend/app/[locale]/dashboard/admin/organizations/page.tsx
@@ -30,6 +30,49 @@ interface Organization {
   createdAt: string;
 }
 
+interface FormData {
+  name: string;
+  type: string;
+  scac: string;
+  siren: string;
+  siret: string;
+  eori: string;
+  contact_phone: string;
+  contact_email: string;
+  address: {
+    street: string;
+    city: string;
+    state: string;
+    postalCode: string;
+    country: string;
+  };
+  logoUrl: string;
+  isActive: boolean;
+}
+
+const EMPTY_FORM: FormData = {
+  name: '',
+  type: 'FREIGHT_FORWARDER',
+  scac: '',
+  siren: '',
+  siret: '',
+  eori: '',
+  contact_phone: '',
+  contact_email: '',
+  address: { street: '', city: '', state: '', postalCode: '', country: 'FR' },
+  logoUrl: '',
+  isActive: true,
+};
+
+function FieldHint({ children }: { children: React.ReactNode }) {
+  return <p className="mt-1 text-xs text-gray-400">{children}</p>;
+}
+
+function FieldError({ message }: { message?: string }) {
+  if (!message) return null;
+  return <p className="mt-1 text-xs text-red-600">{message}</p>;
+}
+
 export default function AdminOrganizationsPage() {
   const t = useTranslations('dashboard.admin.organizations');
 
@@ -40,43 +83,10 @@ export default function AdminOrganizationsPage() {
   const [showCreateModal, setShowCreateModal] = useState(false);
   const [showEditModal, setShowEditModal] = useState(false);
   const [verifyingId, setVerifyingId] = useState<string | null>(null);
-
-  // Form state
-  const [formData, setFormData] = useState<{
-    name: string;
-    type: string;
-    scac: string;
-    siren: string;
-    siret: string;
-    eori: string;
-    contact_phone: string;
-    contact_email: string;
-    address: {
-      street: string;
-      city: string;
-      state?: string;
-      postalCode: string;
-      country: string;
-    };
-    logoUrl: string;
-  }>({
-    name: '',
-    type: 'FREIGHT_FORWARDER',
-    scac: '',
-    siren: '',
-    siret: '',
-    eori: '',
-    contact_phone: '',
-    contact_email: '',
-    address: {
-      street: '',
-      city: '',
-      state: '',
-      postalCode: '',
-      country: 'FR',
-    },
-    logoUrl: '',
-  });
+  const [formData, setFormData] = useState<FormData>(EMPTY_FORM);
+  const [formError, setFormError] = useState<string | null>(null);
+  const [fieldErrors, setFieldErrors] = useState<Partial<Record<string, string>>>({});
+  const [submitting, setSubmitting] = useState(false);
 
   useEffect(() => {
     fetchOrganizations();
@@ -95,70 +105,120 @@ export default function AdminOrganizationsPage() {
     }
   };
 
+  const validateForm = (isCreate: boolean): boolean => {
+    const errors: Partial<Record<string, string>> = {};
+
+    if (!formData.name.trim() || formData.name.trim().length < 2) {
+      errors.name = t('validation.nameTooShort');
+    }
+
+    if (isCreate && formData.type === 'CARRIER') {
+      if (!formData.scac) {
+        errors.scac = t('validation.scacRequired');
+      } else if (!/^[A-Z]{4}$/.test(formData.scac)) {
+        errors.scac = t('validation.scacFormat');
+      }
+    }
+
+    if (formData.siren && !/^[0-9]{9}$/.test(formData.siren)) {
+      errors.siren = t('validation.sirenFormat');
+    }
+
+    if (formData.siret && !/^[0-9]{14}$/.test(formData.siret)) {
+      errors.siret = t('validation.siretFormat');
+    }
+
+    if (!formData.address.street.trim()) errors.street = t('validation.required');
+    if (!formData.address.city.trim()) errors.city = t('validation.required');
+    if (!formData.address.postalCode.trim()) errors.postalCode = t('validation.required');
+    if (!/^[A-Z]{2}$/.test(formData.address.country)) {
+      errors.country = t('validation.countryFormat');
+    }
+
+    setFieldErrors(errors);
+    return Object.keys(errors).length === 0;
+  };
+
+  const buildApiAddress = () => ({
+    street: formData.address.street,
+    city: formData.address.city,
+    postalCode: formData.address.postalCode,
+    country: formData.address.country,
+    ...(formData.address.state ? { state: formData.address.state } : {}),
+  });
+
   const handleCreate = async (e: React.FormEvent) => {
     e.preventDefault();
+    setFormError(null);
+    if (!validateForm(true)) return;
+
+    setSubmitting(true);
     try {
-      const apiData = {
-        name: formData.name,
+      await createOrganization({
+        name: formData.name.trim(),
         type: formData.type as any,
-        address: {
-          street: formData.address.street,
-          city: formData.address.city,
-          postalCode: formData.address.postalCode,
-          country: formData.address.country,
-          ...(formData.address.state ? { state: formData.address.state } : {}),
-        },
+        address: buildApiAddress(),
         contact_email: formData.contact_email || undefined,
         contact_phone: formData.contact_phone || undefined,
-        logo_url: formData.logoUrl || undefined,
+        logoUrl: formData.logoUrl || undefined,
         ...(formData.siren ? { siren: formData.siren } : {}),
         ...(formData.siret ? { siret: formData.siret } : {}),
         ...(formData.eori ? { eori: formData.eori } : {}),
         ...(formData.scac ? { scac: formData.scac } : {}),
-      };
-      await createOrganization(apiData);
+      });
       await fetchOrganizations();
       setShowCreateModal(false);
       resetForm();
     } catch (err: any) {
-      alert(err.message || t('createError'));
+      setFormError(err.message || t('createError'));
+    } finally {
+      setSubmitting(false);
     }
   };
 
   const handleUpdate = async (e: React.FormEvent) => {
     e.preventDefault();
     if (!selectedOrg) return;
+    setFormError(null);
+    if (!validateForm(false)) return;
 
+    setSubmitting(true);
     try {
-      await updateOrganization(selectedOrg.id, formData);
+      await updateOrganization(selectedOrg.id, {
+        name: formData.name.trim(),
+        address: buildApiAddress(),
+        contact_email: formData.contact_email || undefined,
+        contact_phone: formData.contact_phone || undefined,
+        logoUrl: formData.logoUrl || undefined,
+        isActive: formData.isActive,
+        ...(formData.siren ? { siren: formData.siren } : {}),
+        ...(formData.siret ? { siret: formData.siret } : {}),
+        ...(formData.eori ? { eori: formData.eori } : {}),
+      });
       await fetchOrganizations();
       setShowEditModal(false);
       setSelectedOrg(null);
       resetForm();
     } catch (err: any) {
-      alert(err.message || t('updateError'));
+      setFormError(err.message || t('updateError'));
+    } finally {
+      setSubmitting(false);
     }
   };
 
   const resetForm = () => {
-    setFormData({
-      name: '',
-      type: 'FREIGHT_FORWARDER',
-      scac: '',
-      siren: '',
-      siret: '',
-      eori: '',
-      contact_phone: '',
-      contact_email: '',
-      address: {
-        street: '',
-        city: '',
-        state: '',
-        postalCode: '',
-        country: 'FR',
-      },
-      logoUrl: '',
-    });
+    setFormData(EMPTY_FORM);
+    setFormError(null);
+    setFieldErrors({});
+  };
+
+  const handleTypeChange = (newType: string) => {
+    setFormData(prev => ({
+      ...prev,
+      type: newType,
+      scac: newType !== 'CARRIER' ? '' : prev.scac,
+    }));
+    setFieldErrors(prev => ({ ...prev, scac: undefined }));
   };
 
   const handleVerifySiret = async (orgId: string) => {
@@ -222,20 +282,41 @@ export default function AdminOrganizationsPage() {
       eori: org.eori || '',
       contact_phone: org.contact_phone || '',
       contact_email: org.contact_email || '',
-      address: org.address,
+      address: {
+        street: org.address.street,
+        city: org.address.city,
+        state: org.address.state || '',
+        postalCode: org.address.postalCode,
+        country: org.address.country,
+      },
       logoUrl: org.logoUrl || '',
+      isActive: org.isActive,
     });
+    setFormError(null);
+    setFieldErrors({});
     setShowEditModal(true);
   };
 
+  const closeModal = () => {
+    setShowCreateModal(false);
+    setShowEditModal(false);
+    setSelectedOrg(null);
+    resetForm();
+  };
+
   const getTypeLabel = (type: string) => {
     const allowed = ['FREIGHT_FORWARDER', 'CARRIER', 'SHIPPER'];
-    if (allowed.includes(type)) {
-      return t(`types.${type}` as any);
-    }
+    if (allowed.includes(type)) return t(`types.${type}` as any);
     return type.replace('_', ' ');
   };
 
+  const inputClass = (hasError?: string) =>
+    `mt-1 block w-full px-3 py-2 border rounded-md shadow-sm focus:outline-none text-sm ${
+      hasError
+        ? 'border-red-400 focus:border-red-500 focus:ring-red-500'
+        : 'border-gray-300 focus:border-blue-500 focus:ring-blue-500'
+    }`;
+
   if (loading) {
     return (
       <div className="flex items-center justify-center h-96">
@@ -262,7 +343,6 @@ export default function AdminOrganizationsPage() {
         }
       />
 
-      {/* Error Message */}
       {error && (
         <div className="bg-red-50 border border-red-200 text-red-700 px-4 py-3 rounded-lg">
           {error}
@@ -382,247 +462,365 @@ export default function AdminOrganizationsPage() {
         ))}
       </div>
 
-      {/* Create/Edit Modal */}
+      {/* Create / Edit Modal */}
       {(showCreateModal || showEditModal) && (
-        <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50 overflow-y-auto">
-          <div className="bg-white rounded-lg p-6 max-w-2xl w-full m-4 max-h-[90vh] overflow-y-auto">
-            <h2 className="text-xl font-bold mb-4">
+        <div className="fixed inset-0 bg-black bg-opacity-50 flex items-center justify-center z-50 overflow-y-auto py-4">
+          <div className="bg-white rounded-lg p-6 max-w-2xl w-full mx-4 max-h-[90vh] overflow-y-auto">
+            <h2 className="text-xl font-bold mb-6">
               {showCreateModal ? t('modal.createTitle') : t('modal.editTitle')}
             </h2>
-            <form onSubmit={showCreateModal ? handleCreate : handleUpdate} className="space-y-4">
-              <div className="grid grid-cols-2 gap-4">
-                <div className="col-span-2">
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.name')}
-                  </label>
-                  <input
-                    type="text"
-                    required
-                    value={formData.name}
-                    onChange={e => setFormData({ ...formData, name: e.target.value })}
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  />
-                </div>
 
-                <div>
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.type')}
-                  </label>
-                  <select
-                    value={formData.type}
-                    onChange={e => setFormData({ ...formData, type: e.target.value })}
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  >
-                    <option value="FREIGHT_FORWARDER">{t('types.FREIGHT_FORWARDER')}</option>
-                    <option value="CARRIER">{t('types.CARRIER')}</option>
-                    <option value="SHIPPER">{t('types.SHIPPER')}</option>
-                  </select>
-                </div>
-
-                {formData.type === 'CARRIER' && (
-                  <div>
+            <form
+              onSubmit={showCreateModal ? handleCreate : handleUpdate}
+              noValidate
+              className="space-y-5"
+            >
+              {/* ── Informations générales ── */}
+              <section>
+                <h3 className="text-sm font-semibold text-gray-500 uppercase tracking-wide mb-3">
+                  {t('modal.sectionGeneral')}
+                </h3>
+                <div className="grid grid-cols-2 gap-4">
+                  <div className="col-span-2">
                     <label className="block text-sm font-medium text-gray-700">
-                      {t('modal.scacLabel')}
+                      {t('modal.name')} <span className="text-red-500">*</span>
                     </label>
                     <input
                       type="text"
-                      required={formData.type === 'CARRIER'}
-                      maxLength={4}
-                      value={formData.scac}
-                      onChange={e =>
-                        setFormData({ ...formData, scac: e.target.value.toUpperCase() })
-                      }
-                      className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
+                      value={formData.name}
+                      onChange={e => {
+                        setFormData({ ...formData, name: e.target.value });
+                        setFieldErrors(prev => ({ ...prev, name: undefined }));
+                      }}
+                      minLength={2}
+                      maxLength={200}
+                      className={inputClass(fieldErrors.name)}
+                      placeholder="Acme Freight Forwarding"
+                    />
+                    <FieldError message={fieldErrors.name} />
+                  </div>
+
+                  <div>
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.type')} <span className="text-red-500">*</span>
+                    </label>
+                    {showCreateModal ? (
+                      <select
+                        value={formData.type}
+                        onChange={e => handleTypeChange(e.target.value)}
+                        className={inputClass()}
+                      >
+                        <option value="FREIGHT_FORWARDER">{t('types.FREIGHT_FORWARDER')}</option>
+                        <option value="CARRIER">{t('types.CARRIER')}</option>
+                        <option value="SHIPPER">{t('types.SHIPPER')}</option>
+                      </select>
+                    ) : (
+                      <div className="mt-1 flex items-center gap-2">
+                        <span
+                          className={`px-2 py-1 text-xs font-semibold rounded-full ${
+                            formData.type === 'FREIGHT_FORWARDER'
+                              ? 'bg-blue-100 text-blue-800'
+                              : formData.type === 'CARRIER'
+                                ? 'bg-green-100 text-green-800'
+                                : 'bg-purple-100 text-purple-800'
+                          }`}
+                        >
+                          {getTypeLabel(formData.type)}
+                        </span>
+                        <span className="text-xs text-gray-400">{t('modal.typeReadOnly')}</span>
+                      </div>
+                    )}
+                  </div>
+
+                  {/* SCAC — création uniquement, visible en lecture seule en édition si CARRIER */}
+                  {showCreateModal && formData.type === 'CARRIER' && (
+                    <div>
+                      <label className="block text-sm font-medium text-gray-700">
+                        {t('modal.scacLabel')} <span className="text-red-500">*</span>
+                      </label>
+                      <input
+                        type="text"
+                        value={formData.scac}
+                        onChange={e => {
+                          const v = e.target.value.toUpperCase().replace(/[^A-Z]/g, '');
+                          setFormData({ ...formData, scac: v });
+                          setFieldErrors(prev => ({ ...prev, scac: undefined }));
+                        }}
+                        maxLength={4}
+                        minLength={4}
+                        className={inputClass(fieldErrors.scac)}
+                        placeholder="MAEU"
+                      />
+                      <FieldHint>{t('modal.scacHint')}</FieldHint>
+                      <FieldError message={fieldErrors.scac} />
+                    </div>
+                  )}
+                  {showEditModal && formData.type === 'CARRIER' && formData.scac && (
+                    <div>
+                      <label className="block text-sm font-medium text-gray-700">
+                        {t('modal.scacLabel')}
+                      </label>
+                      <div className="mt-1 px-3 py-2 bg-gray-50 border border-gray-200 rounded-md text-sm text-gray-700 font-mono">
+                        {formData.scac}
+                      </div>
+                      <FieldHint>{t('modal.typeReadOnly')}</FieldHint>
+                    </div>
+                  )}
+                </div>
+              </section>
+
+              {/* ── Identifiants légaux ── */}
+              <section>
+                <h3 className="text-sm font-semibold text-gray-500 uppercase tracking-wide mb-3">
+                  {t('modal.sectionLegal')}
+                </h3>
+                <div className="grid grid-cols-2 gap-4">
+                  <div>
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.sirenLabel')}
+                    </label>
+                    <input
+                      type="text"
+                      value={formData.siren}
+                      onChange={e => {
+                        const v = e.target.value.replace(/\D/g, '').slice(0, 9);
+                        setFormData({ ...formData, siren: v });
+                        setFieldErrors(prev => ({ ...prev, siren: undefined }));
+                      }}
+                      maxLength={9}
+                      className={inputClass(fieldErrors.siren)}
+                      placeholder="123456789"
+                    />
+                    <FieldHint>{t('modal.sirenHint')}</FieldHint>
+                    <FieldError message={fieldErrors.siren} />
+                  </div>
+
+                  <div>
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.siretLabel')}
+                    </label>
+                    <input
+                      type="text"
+                      value={formData.siret}
+                      onChange={e => {
+                        const v = e.target.value.replace(/\D/g, '').slice(0, 14);
+                        setFormData({ ...formData, siret: v });
+                        setFieldErrors(prev => ({ ...prev, siret: undefined }));
+                      }}
+                      maxLength={14}
+                      className={inputClass(fieldErrors.siret)}
+                      placeholder="12345678901234"
+                    />
+                    <FieldHint>{t('modal.siretHint')}</FieldHint>
+                    <FieldError message={fieldErrors.siret} />
+                  </div>
+
+                  <div className="col-span-2">
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.eoriLabel')}
+                    </label>
+                    <input
+                      type="text"
+                      value={formData.eori}
+                      onChange={e => setFormData({ ...formData, eori: e.target.value })}
+                      className={inputClass()}
+                      placeholder="FR123456789"
+                    />
+                    <FieldHint>{t('modal.eoriHint')}</FieldHint>
+                  </div>
+                </div>
+              </section>
+
+              {/* ── Contact ── */}
+              <section>
+                <h3 className="text-sm font-semibold text-gray-500 uppercase tracking-wide mb-3">
+                  {t('modal.sectionContact')}
+                </h3>
+                <div className="grid grid-cols-2 gap-4">
+                  <div>
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.contactEmail')}
+                    </label>
+                    <input
+                      type="email"
+                      value={formData.contact_email}
+                      onChange={e => setFormData({ ...formData, contact_email: e.target.value })}
+                      className={inputClass()}
+                      placeholder="contact@exemple.com"
                     />
                   </div>
-                )}
 
-                <div>
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.sirenLabel')}
-                  </label>
-                  <input
-                    type="text"
-                    maxLength={9}
-                    value={formData.siren}
-                    onChange={e => setFormData({ ...formData, siren: e.target.value })}
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  />
+                  <div>
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.contactPhone')}
+                    </label>
+                    <input
+                      type="tel"
+                      value={formData.contact_phone}
+                      onChange={e => setFormData({ ...formData, contact_phone: e.target.value })}
+                      className={inputClass()}
+                      placeholder="+33 6 00 00 00 00"
+                    />
+                  </div>
                 </div>
+              </section>
 
-                <div>
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.siretLabel')}
-                  </label>
-                  <input
-                    type="text"
-                    maxLength={14}
-                    value={formData.siret}
-                    onChange={e =>
-                      setFormData({ ...formData, siret: e.target.value.replace(/\D/g, '') })
-                    }
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                    placeholder={t('modal.siretPlaceholder')}
-                  />
+              {/* ── Adresse ── */}
+              <section>
+                <h3 className="text-sm font-semibold text-gray-500 uppercase tracking-wide mb-3">
+                  {t('modal.sectionAddress')}
+                </h3>
+                <div className="grid grid-cols-2 gap-4">
+                  <div className="col-span-2">
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.street')} <span className="text-red-500">*</span>
+                    </label>
+                    <input
+                      type="text"
+                      value={formData.address.street}
+                      onChange={e => {
+                        setFormData({ ...formData, address: { ...formData.address, street: e.target.value } });
+                        setFieldErrors(prev => ({ ...prev, street: undefined }));
+                      }}
+                      className={inputClass(fieldErrors.street)}
+                      placeholder="123 Rue de la République"
+                    />
+                    <FieldError message={fieldErrors.street} />
+                  </div>
+
+                  <div>
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.city')} <span className="text-red-500">*</span>
+                    </label>
+                    <input
+                      type="text"
+                      value={formData.address.city}
+                      onChange={e => {
+                        setFormData({ ...formData, address: { ...formData.address, city: e.target.value } });
+                        setFieldErrors(prev => ({ ...prev, city: undefined }));
+                      }}
+                      className={inputClass(fieldErrors.city)}
+                      placeholder="Paris"
+                    />
+                    <FieldError message={fieldErrors.city} />
+                  </div>
+
+                  <div>
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.postalCode')} <span className="text-red-500">*</span>
+                    </label>
+                    <input
+                      type="text"
+                      value={formData.address.postalCode}
+                      onChange={e => {
+                        setFormData({ ...formData, address: { ...formData.address, postalCode: e.target.value } });
+                        setFieldErrors(prev => ({ ...prev, postalCode: undefined }));
+                      }}
+                      className={inputClass(fieldErrors.postalCode)}
+                      placeholder="75001"
+                    />
+                    <FieldError message={fieldErrors.postalCode} />
+                  </div>
+
+                  <div>
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.state')}
+                    </label>
+                    <input
+                      type="text"
+                      value={formData.address.state}
+                      onChange={e =>
+                        setFormData({ ...formData, address: { ...formData.address, state: e.target.value } })
+                      }
+                      className={inputClass()}
+                      placeholder="Île-de-France"
+                    />
+                  </div>
+
+                  <div>
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.country')} <span className="text-red-500">*</span>
+                    </label>
+                    <input
+                      type="text"
+                      value={formData.address.country}
+                      onChange={e => {
+                        const v = e.target.value.toUpperCase().replace(/[^A-Z]/g, '').slice(0, 2);
+                        setFormData({ ...formData, address: { ...formData.address, country: v } });
+                        setFieldErrors(prev => ({ ...prev, country: undefined }));
+                      }}
+                      maxLength={2}
+                      minLength={2}
+                      className={inputClass(fieldErrors.country)}
+                      placeholder="FR"
+                    />
+                    <FieldHint>{t('modal.countryHint')}</FieldHint>
+                    <FieldError message={fieldErrors.country} />
+                  </div>
                 </div>
+              </section>
 
-                <div>
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.eoriLabel')}
-                  </label>
-                  <input
-                    type="text"
-                    value={formData.eori}
-                    onChange={e => setFormData({ ...formData, eori: e.target.value })}
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  />
+              {/* ── Autres ── */}
+              <section>
+                <h3 className="text-sm font-semibold text-gray-500 uppercase tracking-wide mb-3">
+                  {t('modal.sectionOther')}
+                </h3>
+                <div className="space-y-4">
+                  <div>
+                    <label className="block text-sm font-medium text-gray-700">
+                      {t('modal.logoUrl')}
+                    </label>
+                    <input
+                      type="url"
+                      value={formData.logoUrl}
+                      onChange={e => setFormData({ ...formData, logoUrl: e.target.value })}
+                      className={inputClass()}
+                      placeholder="https://exemple.com/logo.png"
+                    />
+                  </div>
+
+                  {showEditModal && (
+                    <div className="flex items-center gap-3">
+                      <input
+                        id="isActive"
+                        type="checkbox"
+                        checked={formData.isActive}
+                        onChange={e => setFormData({ ...formData, isActive: e.target.checked })}
+                        className="h-4 w-4 rounded border-gray-300 text-blue-600 focus:ring-blue-500"
+                      />
+                      <label htmlFor="isActive" className="text-sm font-medium text-gray-700">
+                        {t('modal.isActive')}
+                      </label>
+                    </div>
+                  )}
                 </div>
+              </section>
 
-                <div>
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.contactPhone')}
-                  </label>
-                  <input
-                    type="tel"
-                    value={formData.contact_phone}
-                    onChange={e => setFormData({ ...formData, contact_phone: e.target.value })}
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  />
+              {/* Erreur globale */}
+              {formError && (
+                <div className="bg-red-50 border border-red-200 text-red-700 px-4 py-3 rounded-md text-sm">
+                  {formError}
                 </div>
+              )}
 
-                <div>
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.contactEmail')}
-                  </label>
-                  <input
-                    type="email"
-                    value={formData.contact_email}
-                    onChange={e => setFormData({ ...formData, contact_email: e.target.value })}
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  />
-                </div>
-
-                <div className="col-span-2">
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.street')}
-                  </label>
-                  <input
-                    type="text"
-                    required
-                    value={formData.address.street}
-                    onChange={e =>
-                      setFormData({
-                        ...formData,
-                        address: { ...formData.address, street: e.target.value },
-                      })
-                    }
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  />
-                </div>
-
-                <div>
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.city')}
-                  </label>
-                  <input
-                    type="text"
-                    required
-                    value={formData.address.city}
-                    onChange={e =>
-                      setFormData({
-                        ...formData,
-                        address: { ...formData.address, city: e.target.value },
-                      })
-                    }
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  />
-                </div>
-
-                <div>
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.postalCode')}
-                  </label>
-                  <input
-                    type="text"
-                    required
-                    value={formData.address.postalCode}
-                    onChange={e =>
-                      setFormData({
-                        ...formData,
-                        address: { ...formData.address, postalCode: e.target.value },
-                      })
-                    }
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  />
-                </div>
-
-                <div>
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.state')}
-                  </label>
-                  <input
-                    type="text"
-                    value={formData.address.state}
-                    onChange={e =>
-                      setFormData({
-                        ...formData,
-                        address: { ...formData.address, state: e.target.value },
-                      })
-                    }
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  />
-                </div>
-
-                <div>
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.country')}
-                  </label>
-                  <input
-                    type="text"
-                    required
-                    maxLength={2}
-                    value={formData.address.country}
-                    onChange={e =>
-                      setFormData({
-                        ...formData,
-                        address: { ...formData.address, country: e.target.value.toUpperCase() },
-                      })
-                    }
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  />
-                </div>
-
-                <div className="col-span-2">
-                  <label className="block text-sm font-medium text-gray-700">
-                    {t('modal.logoUrl')}
-                  </label>
-                  <input
-                    type="url"
-                    value={formData.logoUrl}
-                    onChange={e => setFormData({ ...formData, logoUrl: e.target.value })}
-                    className="mt-1 block w-full px-3 py-2 border border-gray-300 rounded-md shadow-sm focus:border-blue-500 focus:ring-blue-500 focus:outline-none"
-                  />
-                </div>
-              </div>
-
-              <div className="flex justify-end space-x-2 pt-4">
+              <div className="flex justify-end space-x-3 pt-2 border-t border-gray-100">
                 <button
                   type="button"
-                  onClick={() => {
-                    setShowCreateModal(false);
-                    setShowEditModal(false);
-                    setSelectedOrg(null);
-                    resetForm();
-                  }}
-                  className="px-4 py-2 border border-gray-300 rounded-md text-gray-700 hover:bg-gray-50"
+                  onClick={closeModal}
+                  className="px-4 py-2 border border-gray-300 rounded-md text-sm text-gray-700 hover:bg-gray-50 transition-colors"
                 >
                   {t('modal.cancel')}
                 </button>
                 <button
                   type="submit"
-                  className="px-4 py-2 bg-blue-600 text-white rounded-md hover:bg-blue-700"
+                  disabled={submitting}
+                  className="px-4 py-2 bg-blue-600 text-white rounded-md text-sm font-medium hover:bg-blue-700 disabled:opacity-60 disabled:cursor-not-allowed transition-colors"
                 >
-                  {showCreateModal ? t('modal.create') : t('modal.update')}
+                  {submitting
+                    ? t('modal.saving')
+                    : showCreateModal
+                      ? t('modal.create')
+                      : t('modal.update')}
                 </button>
               </div>
             </form>
diff --git a/apps/frontend/messages/en.json b/apps/frontend/messages/en.json
index d45183e..d88e432 100644
--- a/apps/frontend/messages/en.json
+++ b/apps/frontend/messages/en.json
@@ -1200,24 +1200,46 @@
         "modal": {
           "createTitle": "Create New Organization",
           "editTitle": "Edit Organization",
-          "name": "Organization Name *",
-          "type": "Type *",
-          "scacLabel": "SCAC Code *",
+          "sectionGeneral": "General information",
+          "sectionLegal": "Legal identifiers",
+          "sectionContact": "Contact",
+          "sectionAddress": "Address",
+          "sectionOther": "Other",
+          "name": "Organization name",
+          "type": "Type",
+          "typeReadOnly": "Cannot be changed after creation",
+          "scacLabel": "SCAC code",
+          "scacHint": "4 uppercase letters (e.g. MAEU). Required for carriers.",
           "sirenLabel": "SIREN",
-          "siretLabel": "SIRET (14 digits)",
+          "sirenHint": "9 digits — optional",
+          "siretLabel": "SIRET",
+          "siretHint": "14 digits — optional",
           "siretPlaceholder": "12345678901234",
           "eoriLabel": "EORI",
-          "contactPhone": "Contact Phone",
-          "contactEmail": "Contact Email",
-          "street": "Street Address *",
-          "city": "City *",
-          "postalCode": "Postal Code *",
+          "eoriHint": "EU EORI number (e.g. FR123456789) — optional",
+          "contactEmail": "Contact email",
+          "contactPhone": "Contact phone",
+          "street": "Street address",
+          "city": "City",
+          "postalCode": "Postal code",
           "state": "State / Region",
-          "country": "Country *",
+          "country": "Country",
+          "countryHint": "2-letter ISO code (e.g. FR, DE, US)",
           "logoUrl": "Logo URL",
+          "isActive": "Active organization",
           "cancel": "Cancel",
           "create": "Create",
-          "update": "Update"
+          "update": "Update",
+          "saving": "Saving..."
+        },
+        "validation": {
+          "required": "This field is required",
+          "nameTooShort": "Name must be at least 2 characters",
+          "scacRequired": "SCAC code is required for carriers",
+          "scacFormat": "SCAC must be exactly 4 uppercase letters (e.g. MAEU)",
+          "sirenFormat": "SIREN must be exactly 9 digits",
+          "siretFormat": "SIRET must be exactly 14 digits",
+          "countryFormat": "Country must be a 2-letter ISO code (e.g. FR)"
         }
       },
       "users": {
diff --git a/apps/frontend/messages/fr.json b/apps/frontend/messages/fr.json
index 0220c2e..81a92d8 100644
--- a/apps/frontend/messages/fr.json
+++ b/apps/frontend/messages/fr.json
@@ -1200,24 +1200,46 @@
         "modal": {
           "createTitle": "Créer une nouvelle organisation",
           "editTitle": "Modifier l'organisation",
-          "name": "Nom de l'organisation *",
-          "type": "Type *",
-          "scacLabel": "Code SCAC *",
+          "sectionGeneral": "Informations générales",
+          "sectionLegal": "Identifiants légaux",
+          "sectionContact": "Contact",
+          "sectionAddress": "Adresse",
+          "sectionOther": "Autres",
+          "name": "Nom de l'organisation",
+          "type": "Type",
+          "typeReadOnly": "Non modifiable après création",
+          "scacLabel": "Code SCAC",
+          "scacHint": "4 lettres majuscules (ex. MAEU). Obligatoire pour les transporteurs.",
           "sirenLabel": "SIREN",
-          "siretLabel": "SIRET (14 chiffres)",
+          "sirenHint": "9 chiffres — facultatif",
+          "siretLabel": "SIRET",
+          "siretHint": "14 chiffres — facultatif",
           "siretPlaceholder": "12345678901234",
           "eoriLabel": "EORI",
-          "contactPhone": "Téléphone de contact",
+          "eoriHint": "Numéro EORI européen (ex. FR123456789) — facultatif",
           "contactEmail": "Email de contact",
-          "street": "Rue *",
-          "city": "Ville *",
-          "postalCode": "Code postal *",
+          "contactPhone": "Téléphone de contact",
+          "street": "Rue",
+          "city": "Ville",
+          "postalCode": "Code postal",
           "state": "État / Région",
-          "country": "Pays *",
+          "country": "Pays",
+          "countryHint": "Code ISO 2 lettres majuscules (ex. FR, DE, US)",
           "logoUrl": "URL du logo",
+          "isActive": "Organisation active",
           "cancel": "Annuler",
           "create": "Créer",
-          "update": "Mettre à jour"
+          "update": "Mettre à jour",
+          "saving": "Enregistrement..."
+        },
+        "validation": {
+          "required": "Ce champ est obligatoire",
+          "nameTooShort": "Le nom doit comporter au moins 2 caractères",
+          "scacRequired": "Le code SCAC est obligatoire pour les transporteurs",
+          "scacFormat": "Le code SCAC doit comporter exactement 4 lettres majuscules (ex. MAEU)",
+          "sirenFormat": "Le SIREN doit comporter exactement 9 chiffres",
+          "siretFormat": "Le SIRET doit comporter exactement 14 chiffres",
+          "countryFormat": "Le pays doit être un code ISO à 2 lettres majuscules (ex. FR)"
         }
       },
       "users": {
diff --git a/apps/frontend/src/types/api.ts b/apps/frontend/src/types/api.ts
index 7726daa..d658af9 100644
--- a/apps/frontend/src/types/api.ts
+++ b/apps/frontend/src/types/api.ts
@@ -124,7 +124,7 @@ export interface CreateOrganizationRequest {
   scac?: string;
   contact_email?: string;
   contact_phone?: string;
-  logo_url?: string;
+  logoUrl?: string;
 }
 
 export interface UpdateOrganizationRequest {