Connect JTL-Wawi to DATEV

For a long time, JTL-Wawi handed over invoice data through the DATEV Rechnungsdatenservice 2.0 (invoice data service). DATEV is discontinuing this service on 12/31/2026 and names the Buchungsdatenservice (posting data service) as the successor for JTL customers. It is implemented through the JTL2DATEV solution from JERA. If that works well for you, you need nothing of your own. A custom integration helps when customer accounts, payments or several companies from the Wawi should arrive in DATEV cleanly.

Which data flows from JTL-Wawi to DATEV

1. Outgoing invoice becomes a posting with customer account, revenue account and tax key daily
2. Invoice correction becomes a counter-posting to the original invoice daily
3. Incoming payment from the Wawi's payment matching becomes settlement of the open item daily
4. Customer becomes a debtor (customer account) with a fixed account number and address on creation and change
5. Incoming invoice from procurement becomes a vendor posting daily
6. Invoice PDF becomes a document image with document number with the posting

What already exists for JTL-Wawi and DATEV

DATEV has announced that it will discontinue the Rechnungsdatenservice 2.0 on 12/31/2026. It can no longer be ordered since 01/01/2026. According to DATEV, the switch to the DATEV Buchungsdatenservice was planned for JTL customers in the first quarter of 2026. A JTL service partner writes that the new interface comes from JERA and is available from the JTL Advanced edition.

According to a DATEV employee in the DATEV community, JERA, now part of the JTL group, connects the Wawi to the Buchungsdatenservice with its JTL2DATEV solution. According to DATEV, this service is intended for upstream systems that create postings themselves, and it transfers them together with the digital document images through the DATEV data center. If your edition fits and your tax advisor is happy with the result, this is the obvious route.

Where the standard stops

• Customer accounts do not come along

  In the DATEV community, a user reported in 2023 that with the Rechnungsdatenservice 2.0 the import from JTL runs but customer accounts are not transferred. According to the thread, JTL itself points out that the tax advisor has to rework them.

• No individual customer accounts

  A DATEV employee wrote in the same thread that JTL does not hand over customer accounts through the Rechnungsdatenservice 2.0, and recommended collective customer accounts. Firms working with individual customer accounts should check in advance whether the new route through the Buchungsdatenservice changes this.

• Edition and cost

  If the new interface requires a higher JTL edition, the switch becomes a licensing question. For small merchants, a lean custom export can be cheaper than the upgrade.

• Several companies in one Wawi

  If the Wawi manages several companies, each needs its own DATEV client with its own batch and accounts. The handover has to separate them cleanly.

• Tax keys for EU deliveries

  Tax-exempt intra-community deliveries and OSS (One-Stop Shop) sales need their own tax rates and keys in the Wawi. If they are missing there, the revenue lands on the wrong account, and your tax advisor has to rebook.

How we build the integration

JTL side: We read preferably through the JTL-Wawi API, a REST interface available for the local installation and for the cloud. The application is registered there with an app ID and API key. Where the API does not provide a field, we read from the Wawi database, which runs on Microsoft SQL Server, in read-only mode and only through our own views without write permissions. If the Wawi runs on a server in your office, a small service runs in the local network and transfers data encrypted.

DATEV side: Postings go as a posting batch (Buchungsstapel) in the DATEV format. We hand over customer accounts in the separate master data file of the DATEV format, so that name and address reach your tax advisor. Whether the files go to your tax advisor or are transferred online depends on the client's DATEV order. The guide DATEV API access explains the routes.

Control: Before every export, the integration checks that each invoice has a tax key and each customer has an account number. Gaps are reported before the batch is created. The log records which invoice was in which batch.

Process and price range

A free 30-minute check clarifies edition, companies, chart of accounts and your tax advisor's requirements. A fixed price follows within 3 working days. The connection from JTL-Wawi to DATEV starts at €1,900 net and usually goes live after 2 to 4 weeks. See Process and pricing.

Updated: 10/21/2026