diff --git a/src/app/api/purchase-orders/upload/route.ts b/src/app/api/purchase-orders/upload/route.ts
index e9b920e..ae7fb86 100644
--- a/src/app/api/purchase-orders/upload/route.ts
+++ b/src/app/api/purchase-orders/upload/route.ts
@@ -61,8 +61,27 @@ export async function POST(request: Request) {
       attempts: 0,
     });
   } catch (err) {
-    console.error("[po-upload] batch_create failed", { err: String(err) });
-    return NextResponse.json({ error: "batch_create_failed" }, { status: 500 });
+    // PocketBase's ClientResponseError carries the per-field validation
+    // details on err.response.data — surface them so the user can see
+    // exactly what went wrong (e.g. mime type not allowed, missing field).
+    const e = err as {
+      status?: number;
+      response?: { code?: number; data?: unknown; message?: string };
+    };
+    console.error("[po-upload] batch_create failed", {
+      err: String(err),
+      status: e?.status,
+      response: e?.response,
+    });
+    return NextResponse.json(
+      {
+        error: "batch_create_failed",
+        pb_status: e?.status ?? null,
+        pb_message: e?.response?.message ?? null,
+        pb_data: e?.response?.data ?? null,
+      },
+      { status: 500 },
+    );
   }
 
   console.log("[po-upload] queued", {