
German Tax Updates in December 2025
1. Tax Return: 2026 Is Just Around the Corner – File Your Voluntary 2021 Tax Return Now and Benefit It feels like 2025 has only just begun, yet the end of the year is already fast approaching.Anyone who was not required to file a tax return for 2021 and has also not submitted a voluntary return should act quickly. The reason is simple: any tax refund for 2021 will be forfeited if the return has not been submitted to the tax office by 31 December, 2025. Applying for a favourable tax assessment under Section 32d (6) of the German Income Tax Act (EStG) after that date will not help. A taxpayer recently learned this the hard way before the German Federal Fiscal Court (BFH). The Assessment Period for Voluntary Tax Returns The tax office may only issue a tax assessment if the relevant assessment period (Festsetzungsfrist) has not yet expired. Once this period ends, the tax claim itself lapses (§ 47 German Fiscal Code – AO). As a result, any tax assessments issued after the expiration of the assessment period are unlawful (though not void) and may be challenged by filing a timely objection. Under § 169(2) no. 2 AO,




