---
title: "DATEV cost category ID error for Administrators - Payhawk Help Center"
slug: "failed-to-export-into-datev-the-selected-cost-category-does-not-have-an-external-id-associated-with-it"
description: "Fix the DATEV export error about a cost category without an external ID: select another cost category, then select the correct one again and retry the export."
updated: 2026-02-26T13:36:29Z
published: 2026-02-26T13:36:29Z
canonical: "payhawk.com/failed-to-export-into-datev-the-selected-cost-category-does-not-have-an-external-id-associated-with-it"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://payhawk.com/help/llms.txt
> Use this file to discover all available pages before exploring further.

# Failed to export into Datev. The selected cost category does not have an external ID associated with it.

## Error message

```plaintext
Failed to export into Datev. The selected cost category does not have an external ID associated with it.
```

## Affected ERP integrations

- DATEV

## Cause

This error occurs when the cost category was selected before its external ID mapping was completed in DATEV. Because mappings are applied to historical data, Payhawk does not automatically refresh old fields after the mapping is added.

## Solution

To resolve this issue:

1. Open the affected expense line in Payhawk.
2. Briefly select a different cost category.
3. Reselect the correct cost category (the one now linked to an external ID).
4. Save your changes and trigger the export again.