# DATEV Unternehmen online

Post to DATEV Unternehmen online.

Cortena can connect to **DATEV Unternehmen online (DUo)** so approved payables land in the DATEV environment your tax advisor or finance team already uses.

**Who this is for:** German entities that post through Unternehmen online rather than (or in addition to) DATEV Rechnungswesen / Buchungsstapel.

## Before you start

1. Confirm you have admin access to the DATEV organisation you want to connect.
2. Know which **Mandant** Cortena should use.
3. Complete Cortena matching guidelines so booking accounts and VAT codes align with DATEV.

For Rechnungswesen / EXTF export, see [DATEV Rechnungswesen](https://help.cortena.ai/guides/integrations/datev-rechnungswesen).

## Connect in Cortena

1. Open **Settings → Integrations → DATEV**.
2. Choose **Unternehmen online** as the DATEV target (wording may appear as DUo / Unternehmen online).
3. Complete the OAuth / DATEV login and grant Cortena the required scopes.
4. Select the correct company / Mandant.
5. Sync reference data (creditors, accounts, tax keys) before the first production export.

## Day-to-day export

1. Match and approve invoices in Cortena as usual.
2. Export from the invoice list or detail when the workflow reaches the DATEV export step.
3. Confirm the batch appears in Unternehmen online.
4. Check the invoice **Activity** log if an export fails or stalls.

## Common issues

| Symptom | What to try |
| --- | --- |
| Connection fails | Confirm DATEV admin rights and reconnect from Settings → Integrations |
| Wrong Mandant | Re-open DATEV settings and select the correct company |
| Permission / RDS errors | Ask your DATEV administrator to grant Rechnungsdatenservice access for the Mandant |
| Fields missing after export | Resolve Needs review flags in Cortena, then re-export |

## Related

- [Connecting your accounting system](https://help.cortena.ai/guides/get-started/connecting-accounting)
- [DATEV Rechnungswesen](https://help.cortena.ai/guides/integrations/datev-rechnungswesen)
- [Troubleshooting](https://help.cortena.ai/guides/support/troubleshooting)

For DATEV permission errors during setup, contact [support@cortena.ai](mailto:support@cortena.ai) with the Mandant and error text.