August 6, 2025, 11:47 am | Read time: 3 minutes
After the submission deadline, the responsible tax office takes a close look at the submitted tax return. They use extensive data sources, automated audit programs, and targeted checks to uncover discrepancies. Whether a mistake is made accidentally or intentionally doesn’t matter, because without timely correction, high back payments, fines, or even criminal consequences can threaten.
Automated Audits and Data Matching
As soon as your tax return reaches the tax office, it first goes through an automated audit program. The software is trained to detect discrepancies and flags suspicious cases for manual review. In particular, the clerks take a closer look if you claim a home office, dual household management, or many home office days. Additionally, the tax offices have numerous automatically transmitted data, such as from employers, social security institutions, or insurance companies.
Information Sources at Home and Abroad
The tax offices do not limit themselves to domestic data. Through the automatic exchange of account information with many countries, they also receive clues about assets abroad. Banks report relevant account data directly to the Federal Central Tax Office. Notaries transmit information on real estate purchases and sales, and audits reveal irregularities in companies. Anonymous tips–such as from former business partners or neighbors–can also trigger investigations.
Special Attention to Suspicious Information
Very high donations, above-average advertising expenses, or undeclared side income quickly attract the interest of auditors, mentions the business magazine “Capital.” Anyone who fails to report a property sale, inheritance, or gift risks being accused of tax evasion. In certain cases, officials may even view your account with judicial approval.
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Consequences, Correction, and Prevention
Those who intentionally provide false information risk fines or imprisonment, depending on the amount of tax evaded. For negligent errors, the penalties are generally milder, but back payments and interest are still a threat. A timely voluntary disclosure can bring immunity in both cases–provided it is complete and made before the tax office discovers the error.
Also read: What the Tax Office Knows About You
If you discover an error, you should report it immediately, preferably before receiving the tax assessment or in a timely manner via an appeal. Even after the assessment is issued, there are correction options under certain conditions, such as a “simple amendment.” To avoid problems from the outset, it is advisable to keep accurate records of all income and expenses. In complex or international cases, professional assistance can be helpful.
Errors by the Tax Office
If the tax office errs in your favor and your information is correct and complete, you generally do not have to report the error, writes the magazine “Finanztip.” Often, a final tax assessment cannot later be changed to your disadvantage–provided you did not cause the error yourself. A subsequent change is usually only possible under strict legal conditions and is specifically pursued by the authorities.