diff --git a/client/src/pages/BapHistory.tsx b/client/src/pages/BapHistory.tsx
index b11515c..07f8e6b 100644
--- a/client/src/pages/BapHistory.tsx
+++ b/client/src/pages/BapHistory.tsx
@@ -291,11 +291,21 @@ export default function BapHistory() {
                               )}
                             </div>
                           ) : (entry as any).sharepointUploadStatus === 'error' ? (
-                            <div className="flex items-center gap-1" title={(entry as any).sharepointUploadError || 'Erreur SharePoint'}>
-                              <div className="flex items-center gap-1 text-red-600">
-                                <CloudOff className="h-3.5 w-3.5" />
-                                <span className="text-xs">SP Erreur</span>
+                            <div
+                              className="flex items-center gap-1 cursor-help"
+                              title={(entry as any).sharepointUploadError || 'Erreur SharePoint'}
+                            >
+                              <div className="flex items-center gap-1 text-red-600 border border-red-200 bg-red-50 rounded px-1.5 py-0.5">
+                                <CloudOff className="h-3.5 w-3.5 shrink-0" />
+                                <span className="text-xs font-medium">SP Erreur</span>
                               </div>
+                              {(entry as any).sharepointUploadError && (
+                                <span
+                                  className="hidden group-hover:block absolute z-50 max-w-xs bg-gray-900 text-white text-xs rounded p-2 shadow-lg"
+                                >
+                                  {(entry as any).sharepointUploadError}
+                                </span>
+                              )}
                             </div>
                           ) : entry.exportPath ? (
                             <div className="flex items-center gap-1">
diff --git a/client/src/pages/ImportSettings.tsx b/client/src/pages/ImportSettings.tsx
index 2c06c1e..a287001 100644
--- a/client/src/pages/ImportSettings.tsx
+++ b/client/src/pages/ImportSettings.tsx
@@ -34,6 +34,7 @@ export default function ImportSettings() {
   const startFolderServiceMutation = trpc.folderImportService.start.useMutation();
   const stopFolderServiceMutation = trpc.folderImportService.stop.useMutation();
   const testAzureConnectionMutation = trpc.importSettings.testAzureConnection.useMutation();
+  const testSharePointUploadMutation = trpc.importSettings.testSharePointUpload.useMutation();
 
   // Manual import
   const [manualImportEnabled, setManualImportEnabled] = useState(true);
@@ -770,6 +771,47 @@ export default function ImportSettings() {
                             </Button>
                             <p className="text-xs text-muted-foreground mt-1">Vérifie le token OAuth2 et l'accès au site SharePoint</p>
                           </div>
+
+                          {/* Bouton test upload réel */}
+                          <div className="pt-1">
+                            <Button
+                              type="button"
+                              variant="outline"
+                              size="sm"
+                              onClick={async () => {
+                                try {
+                                  const result = await testSharePointUploadMutation.mutateAsync();
+                                  if (result.success) {
+                                    toast.success(
+                                      result.webUrl
+                                        ? `Fichier test déposé avec succès ! Cliquez pour l'ouvrir`
+                                        : `Fichier test déposé avec succès dans SharePoint`,
+                                      {
+                                        duration: 8000,
+                                        action: result.webUrl ? { label: 'Ouvrir', onClick: () => window.open(result.webUrl!, '_blank') } : undefined,
+                                      }
+                                    );
+                                  } else {
+                                    toast.error(`Échec upload test : ${result.error}`, { duration: 10000 });
+                                    if ((result as any).debugInfo) {
+                                      console.error('[SharePoint debug]', (result as any).debugInfo);
+                                    }
+                                  }
+                                } catch (e: any) {
+                                  toast.error("Erreur : " + (e?.message || "impossible de tester l'upload"));
+                                }
+                              }}
+                              disabled={testSharePointUploadMutation.isPending || !azureTenantId || !azureClientId || !azureClientSecret || !exportFolder}
+                              className="gap-2 border-blue-300 text-blue-700 hover:bg-blue-50"
+                            >
+                              {testSharePointUploadMutation.isPending ? (
+                                <><Loader2 className="h-4 w-4 animate-spin" />Upload test en cours...</>
+                              ) : (
+                                <><Upload className="h-4 w-4" />Tester l'upload SharePoint</>
+                              )}
+                            </Button>
+                            <p className="text-xs text-muted-foreground mt-1">Dépose un fichier texte de 1 Ko dans le dossier SharePoint pour valider les permissions d'upload</p>
+                          </div>
                         </div>
                       </div>
                     )}
diff --git a/server/routers.ts b/server/routers.ts
index 015dc4c..3f57ab1 100644
--- a/server/routers.ts
+++ b/server/routers.ts
@@ -1569,6 +1569,54 @@ export const appRouter = router({
           return { success: false, error: err.message || 'Erreur inconnue' };
         }
       }),
+
+    testSharePointUpload: protectedProcedure
+      .mutation(async ({ ctx }) => {
+        const settings = await getImportSettingsByUser(ctx.user.id);
+        const tenantId = (settings as any)?.azureTenantId;
+        const clientId = (settings as any)?.azureClientId;
+        const clientSecret = (settings as any)?.azureClientSecret;
+        const sharepointUrl = settings?.exportFolder;
+
+        if (!tenantId || !clientId || !clientSecret) {
+          return { success: false, error: 'Credentials Azure AD manquants (Tenant ID, Client ID ou Secret)' };
+        }
+        if (!sharepointUrl) {
+          return { success: false, error: 'URL SharePoint non configurée dans le dossier d\'export' };
+        }
+
+        try {
+          const { uploadToSharePoint } = await import('./sharepoint');
+          // Créer un fichier test de 1 Ko
+          const testContent = `Test upload SharePoint - ${new Date().toISOString()}\nApplication : Dématérialisation Facturation\nCe fichier peut être supprimé.`;
+          const testBuffer = Buffer.from(testContent, 'utf-8');
+          const testFileName = `test-upload-${Date.now()}.txt`;
+
+          const result = await uploadToSharePoint(
+            { tenantId, clientId, clientSecret, sharepointUrl },
+            testBuffer,
+            testFileName
+          );
+
+          if (result.success) {
+            return {
+              success: true,
+              message: `Fichier test déposé avec succès dans SharePoint`,
+              webUrl: result.webUrl,
+              fileName: testFileName,
+              debugInfo: result.debugInfo,
+            };
+          } else {
+            return {
+              success: false,
+              error: result.error || 'Échec de l\'upload test',
+              debugInfo: result.debugInfo,
+            };
+          }
+        } catch (err: any) {
+          return { success: false, error: err.message || 'Erreur inconnue' };
+        }
+      }),
   }),
   
   // ============= DEPARTMENT LIST ROUTES =============