diff --git a/front/public/locales/en/operationalStudies/importTrainSchedule.json b/front/public/locales/en/operationalStudies/importTrainSchedule.json
index b31e39f13c3..91a8f5779b0 100644
--- a/front/public/locales/en/operationalStudies/importTrainSchedule.json
+++ b/front/public/locales/en/operationalStudies/importTrainSchedule.json
@@ -15,6 +15,10 @@
     "errorSameFromTo": "Origin and destination must be different",
     "errorInvalidFile": "Invalid file"
   },
+  "warningMessages": {
+    "warning": "Warning",
+    "warningFilteredStepImport": "Some invalid steps had to be removed to allow import for trains: {{trainNumbers}}"
+  },
   "failure": "Operation failed",
   "from": "Origin",
   "import": "Import",
diff --git a/front/public/locales/fr/operationalStudies/importTrainSchedule.json b/front/public/locales/fr/operationalStudies/importTrainSchedule.json
index 42bcab0ef1c..27f08cdad8a 100644
--- a/front/public/locales/fr/operationalStudies/importTrainSchedule.json
+++ b/front/public/locales/fr/operationalStudies/importTrainSchedule.json
@@ -15,6 +15,10 @@
     "errorSameFromTo": "L'origine et la destination doivent être différentes.",
     "errorInvalidFile": "Fichier invalide"
   },
+  "warningMessages": {
+    "warning": "Attention",
+    "warningFilteredStepImport": "Certaines étapes invalides ont dû être supprimées pour permettre l'importation pour les trains : {{trainNumbers}}"
+  },
   "failure": "Opération échouée",
   "from": "Origine",
   "import": "Importation",
diff --git a/front/src/modules/trainschedule/components/ImportTrainSchedule/ImportTrainScheduleConfig.tsx b/front/src/modules/trainschedule/components/ImportTrainSchedule/ImportTrainScheduleConfig.tsx
index 3e9cbfcfc57..6286e0e40b5 100644
--- a/front/src/modules/trainschedule/components/ImportTrainSchedule/ImportTrainScheduleConfig.tsx
+++ b/front/src/modules/trainschedule/components/ImportTrainSchedule/ImportTrainScheduleConfig.tsx
@@ -19,7 +19,7 @@ import { ModalContext } from 'common/BootstrapSNCF/ModalSNCF/ModalProvider';
 import StationCard from 'common/StationCard';
 import UploadFileModal from 'common/uploadFileModal';
 import StationSelector from 'modules/trainschedule/components/ImportTrainSchedule/ImportTrainScheduleStationSelector';
-import { setFailure } from 'reducers/main';
+import { setFailure, setWarning } from 'reducers/main';
 import { useAppDispatch } from 'store';
 import { formatIsoDate } from 'utils/date';
 
@@ -53,6 +53,37 @@ const ImportTrainScheduleConfig = ({
   const dispatch = useAppDispatch();
   const { openModal, closeModal } = useContext(ModalContext);
 
+  function filterInvalidSteps(
+    importedTrainSchedules: ImportedTrainSchedule[]
+  ): ImportedTrainSchedule[] {
+    const trainNumbersOfModifiedTrains: string[] = [];
+
+    const filteredSchedules = importedTrainSchedules.map((trainSchedule) => {
+      const filteredSteps = trainSchedule.steps.filter(
+        (step, i) =>
+          i === 0 ||
+          new Date(step.arrivalTime).getTime() >=
+            new Date(trainSchedule.steps[i - 1].departureTime).getTime()
+      );
+      if (filteredSteps.length < trainSchedule.steps.length) {
+        trainNumbersOfModifiedTrains.push(trainSchedule.trainNumber);
+      }
+      return { ...trainSchedule, steps: filteredSteps };
+    });
+
+    if (trainNumbersOfModifiedTrains.length)
+      dispatch(
+        setWarning({
+          title: t('warningMessages.warning'),
+          text: t('warningMessages.warningFilteredStepImport', {
+            trainNumbers: trainNumbersOfModifiedTrains,
+          }),
+        })
+      );
+
+    return filteredSchedules;
+  }
+
   function validateImportedTrainSchedules(
     importedTrainSchedules: Record<string, unknown>[]
   ): ImportedTrainSchedule[] | null {
@@ -81,7 +112,7 @@ const ImportTrainScheduleConfig = ({
       );
       return null;
     }
-    return importedTrainSchedules as ImportedTrainSchedule[];
+    return filterInvalidSteps(importedTrainSchedules as ImportedTrainSchedule[]);
   }
 
   function updateTrainSchedules(importedTrainSchedules: ImportedTrainSchedule[]) {
diff --git a/front/src/modules/trainschedule/components/ImportTrainSchedule/generateTrainSchedulesPayloads.ts b/front/src/modules/trainschedule/components/ImportTrainSchedule/generateTrainSchedulesPayloads.ts
index 06cc096fbd9..5c15563c97b 100644
--- a/front/src/modules/trainschedule/components/ImportTrainSchedule/generateTrainSchedulesPayloads.ts
+++ b/front/src/modules/trainschedule/components/ImportTrainSchedule/generateTrainSchedulesPayloads.ts
@@ -34,8 +34,9 @@ export function generateTrainSchedulesPayloads(
           console.error(`Invalid CH code for step ${step.name}`);
           return acc; // Skip invalid step
         }
-
-        acc.path.push({ id: stepId, uic: Number(step.uic), secondary_code: step.chCode });
+        if (!step.uic && step.trigram)
+          acc.path.push({ id: stepId, trigram: step.trigram, secondary_code: step.chCode });
+        else acc.path.push({ id: stepId, uic: Number(step.uic), secondary_code: step.chCode });
 
         // Skip first step, handle time differences
         if (index !== 0) {