Estimates due to technical errors? When data exports to the tax office become a tax risk

The cash register is the central hub of any hotel and gastronomy business – from breakfast rolls to the last round at the bar. Since 2023, even a technical error during a data export can call the accuracy of bookkeeping into question. If POS data isn’t provided in the required standard format, tax authorities are allowed to estimate revenues – in extreme cases, even fully. The legal basis for this is § 158 (2) No. 2 of the German Fiscal Code (AO).

What applies to data exports?

Form over substance. If digital interfaces or export formats are incorrect, incomplete, or incompatible, then clean data exports matter more than good intentions. Even correctly booked sales don’t automatically protect you from estimates.

The obligation to export data correctly doesn’t only apply to the POS system in the narrow sense. It specifically affects three areas:

• TSE (Technical Security Device): Since January 1, 2020, electronic recording systems are required to use a certified TSE (legal basis since 2016). Data recorded via the POS must be made available in standardized form during audits – in accordance with § 146a AO and the KassenSichV/DSFinV-K regulations.
• DLS (Digital Wage Interface): Mandatory since 2018. Payroll accounts must be exported in a standardized format for external payroll audits – regardless of the software used (see § 41 (1) Sentence 7 EStG in conjunction with § 4 (2a) LStDV).
• Coming soon: Unified data interface for external audits. The Federal Ministry of Finance is currently working on a regulation introducing standard digital interfaces and data format descriptions for exporting bookkeeping data subject to retention (§ 147b AO).

Why is gastronomy especially affected?

Many businesses use solid but outdated POS systems or isolated solutions that work reliably day-to-day but hit their limits when it comes to exporting data.

Operations are complex: tables are merged or split, bills are divided, orders canceled, happy hour prices vary, dine-in and takeout must be clearly separated – plus delivery services, vouchers, and tips. All of this needs to appear in the exported data package in a consistent and traceable manner – including timestamps, staff IDs, payment types, and TSE information.

If the export doesn’t run smoothly during an audit, the risk of revenue estimation increases.

Your 5-step practical plan

1. Test your data export now.
Run a full test export of your POS data in the required standard format. Check if the file opens correctly and if receipts, cancellations, transfers, payment types, staff IDs, timestamps, and TSE data are accurate. Record the date, system version, and outcome in a short log.

2. Updates and system upgrades.
Talk to your POS provider about available updates to interfaces or formats and how to stabilize your export. Be realistic: replacing very old systems in time is often cheaper than facing disputes and estimates later.

3. Keep procedural documentation short and clear.
Describe who does what and how: operating the register, user roles and permissions, cancellation approvals, daily closing, and data export. Document hospitality-specific scenarios like table changes, bill splitting, vouchers, deliveries, events, and tips. Date any changes – that’s all you need.

4. Simulate an audit.
Do a dry run: can you deliver complete, auditable, standard-format data – without stress or last-minute fixes? If you spot any gaps, that’s your to-do list for your provider, IT team, and staff training.

5. Train your team.
Offer short training sessions for service staff and bartenders: correct button sequences, cancellations, transfers, tips. A quick POS guide (1–2 pages) placed visibly at the point of sale helps prevent everyday mistakes and saves nerves in real audits.

Conclusion

Technology plays a key role.
Those who can export POS data in a standardized, complete, and auditable format – and use the DLS properly for payroll – leave auditors with little room for estimates. This can often prevent additional taxation.

And even if estimates are made, here’s our clear position: Formal errors are no substitute for real substance. In our view, § 158 (2) No. 2 AO breaks with previous case law, which allowed estimates only in the case of serious formal defects. Estimates shouldn’t be used as a disciplinary tool but must reflect the actual situation of the business. Excessive estimates are frequently reduced by courts if the tax office’s justification doesn’t hold up.

That’s why it’s now more important than ever to be “export-ready,” to document processes efficiently, and to train your team. That way, your POS system remains what it’s meant to be: a profit driver – not a risk.

Do you have questions about data export and possible estimates due to technical errors? Please feel free to contact us.