diff --git a/frontend/modules/transport/pages/carriers/[id]/edit.vue b/frontend/modules/transport/pages/carriers/[id]/edit.vue
index 00f61e3..0ab84ac 100644
--- a/frontend/modules/transport/pages/carriers/[id]/edit.vue
+++ b/frontend/modules/transport/pages/carriers/[id]/edit.vue
@@ -25,14 +25,19 @@
                     :required="true"
                     :error="mainErrors.errors.name"
                 />
-                <MalioInputText
-                    v-if="isLiot"
-                    v-model="main.liotPlates"
-                    :label="t('transport.carriers.form.main.liotPlates')"
-                    :hint="t('transport.carriers.form.main.liotPlatesHint')"
-                    :required="true"
-                    :error="mainErrors.errors.liotPlates"
-                />
+                <!-- Cas LIOT : le champ immatriculations occupe les colonnes restantes
+                     de la ligne (3 en xl, 2 sinon). Wrapper pour le col-span car
+                     MalioInputText (inheritAttrs:false) renvoie `class` sur l'input. -->
+                <div v-if="isLiot" class="col-span-2 xl:col-span-3">
+                    <MalioInputText
+                        :model-value="main.liotPlates"
+                        @update:model-value="(v: string) => main.liotPlates = sanitizeLiotPlates(v)"
+                        :label="t('transport.carriers.form.main.liotPlates')"
+                        :hint="t('transport.carriers.form.main.liotPlatesHint')"
+                        :required="true"
+                        :error="mainErrors.errors.liotPlates"
+                    />
+                </div>
                 <template v-if="!isLiot">
                     <MalioSelect
                         :model-value="main.certificationType"
@@ -214,7 +219,7 @@ import CarrierQualimatTab from '~/modules/transport/components/CarrierQualimatTa
 import { useCarrierForm } from '~/modules/transport/composables/useCarrierForm'
 import { useCarrier } from '~/modules/transport/composables/useCarrier'
 import type { QualimatCarrierRow } from '~/modules/transport/composables/useQualimatSearch'
-import { clampPercent, sanitizeDecimal } from '~/modules/transport/utils/forms/numberInput'
+import { clampPercent, sanitizeDecimal, sanitizeLiotPlates } from '~/modules/transport/utils/forms/numberInput'
 import { sanitizeFreeText } from '~/shared/utils/textSanitize'
 
 interface SelectOption {
diff --git a/frontend/modules/transport/pages/carriers/new.vue b/frontend/modules/transport/pages/carriers/new.vue
index f477ea8..3688caf 100644
--- a/frontend/modules/transport/pages/carriers/new.vue
+++ b/frontend/modules/transport/pages/carriers/new.vue
@@ -27,16 +27,21 @@
                 :error="mainErrors.errors.name"
             />
 
-            <!-- Cas LIOT : seul le champ immatriculations est pertinent. -->
-            <MalioInputText
-                v-if="isLiot"
-                v-model="main.liotPlates"
-                :label="t('transport.carriers.form.main.liotPlates')"
-                :hint="t('transport.carriers.form.main.liotPlatesHint')"
-                :required="true"
-                :disabled="mainLocked"
-                :error="mainErrors.errors.liotPlates"
-            />
+            <!-- Cas LIOT : seul le champ immatriculations est pertinent. Il occupe
+                 les colonnes restantes de la ligne (3 en xl, 2 sinon) — le wrapper
+                 porte le col-span car MalioInputText (inheritAttrs:false) renvoie
+                 `class` sur l'input interne, pas sur la cellule de grille. -->
+            <div v-if="isLiot" class="col-span-2 xl:col-span-3">
+                <MalioInputText
+                    :model-value="main.liotPlates"
+                    @update:model-value="(v: string) => main.liotPlates = sanitizeLiotPlates(v)"
+                    :label="t('transport.carriers.form.main.liotPlates')"
+                    :hint="t('transport.carriers.form.main.liotPlatesHint')"
+                    :required="true"
+                    :disabled="mainLocked"
+                    :error="mainErrors.errors.liotPlates"
+                />
+            </div>
 
             <!-- Cas standard : certification + affretement + champs conditionnels. -->
             <template v-if="!isLiot">
@@ -308,7 +313,7 @@ import CarrierPriceBlock from '~/modules/transport/components/CarrierPriceBlock.
 import CarrierQualimatTab from '~/modules/transport/components/CarrierQualimatTab.vue'
 import { useCarrierForm } from '~/modules/transport/composables/useCarrierForm'
 import type { QualimatCarrierRow } from '~/modules/transport/composables/useQualimatSearch'
-import { clampPercent, sanitizeDecimal } from '~/modules/transport/utils/forms/numberInput'
+import { clampPercent, sanitizeDecimal, sanitizeLiotPlates } from '~/modules/transport/utils/forms/numberInput'
 import { sanitizeFreeText } from '~/shared/utils/textSanitize'
 
 interface SelectOption {
diff --git a/frontend/modules/transport/utils/forms/__tests__/numberInput.test.ts b/frontend/modules/transport/utils/forms/__tests__/numberInput.test.ts
index fff0a56..eeba136 100644
--- a/frontend/modules/transport/utils/forms/__tests__/numberInput.test.ts
+++ b/frontend/modules/transport/utils/forms/__tests__/numberInput.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest'
-import { clampPercent, sanitizeDecimal } from '../numberInput'
+import { clampPercent, sanitizeDecimal, sanitizeLiotPlates } from '../numberInput'
 
 describe('numberInput — saisie volume / indexation (ERP-170)', () => {
     it('sanitizeDecimal : ne garde que chiffres + un seul point', () => {
@@ -19,4 +19,12 @@ describe('numberInput — saisie volume / indexation (ERP-170)', () => {
         expect(clampPercent('12,5')).toBe('12,5') // ≤ 100 → inchangé
         expect(clampPercent('')).toBe('')
     })
+
+    it('sanitizeLiotPlates : garde lettres/chiffres/tiret/point-virgule, retire espaces et reste', () => {
+        expect(sanitizeLiotPlates('AB-123-CD;EF-456-GH')).toBe('AB-123-CD;EF-456-GH')
+        expect(sanitizeLiotPlates('ab-123-cd ; ef-456-gh')).toBe('ab-123-cd;ef-456-gh') // espaces retirés
+        expect(sanitizeLiotPlates('AB 123 CD')).toBe('AB123CD') // espaces retirés
+        expect(sanitizeLiotPlates('AB.123/CD#42')).toBe('AB123CD42') // . / # retirés
+        expect(sanitizeLiotPlates('')).toBe('')
+    })
 })
diff --git a/frontend/modules/transport/utils/forms/numberInput.ts b/frontend/modules/transport/utils/forms/numberInput.ts
index 29f9f8e..79b8d98 100644
--- a/frontend/modules/transport/utils/forms/numberInput.ts
+++ b/frontend/modules/transport/utils/forms/numberInput.ts
@@ -26,3 +26,13 @@ export function clampPercent(value: string): string {
     const n = Number(String(value ?? '').replace(',', '.').replace(/\s/g, ''))
     return (!Number.isNaN(n) && n > 100) ? '100' : value
 }
+
+/**
+ * Restreint la saisie des immatriculations LIOT : ne garde que lettres, chiffres,
+ * tiret et point-virgule (séparateur de plaques). Les espaces et tout autre
+ * caractère sont supprimés à la frappe / au collage. La normalisation finale
+ * (majuscules + « ; » espacé) reste au back (RG-4.13).
+ */
+export function sanitizeLiotPlates(value: string): string {
+    return (value ?? '').replace(/[^A-Za-z0-9;-]/g, '')
+}