The increasingly complex German tax system leads to tax assessments issued by the tax authorities being partially incorrect not only due to errors but also occasionally due to incorrect interpretations of the law. Additionally, incorrect tax assessments can be caused by the taxpayer if, for example, due to a lack of knowledge of tax law, they do not fully or incorrectly declare certain facts, and this is not recognized by the competent tax authority. Both situations are unfortunate and crucial for the need to correct tax assessments when and to the extent that the Tax Code allows for such corrections.

The correction provisions of the Tax Code attempt to bridge the opposing principles of legal certainty and substantive legal correctness by breaking the substantive finality. This book demonstrates that the Tax Code, as a superior 'fundamental law' for individual tax laws, provides extensive options for amendments for a variety of errors, particularly when these errors may adversely affect the taxpayer. Conversely—and this is equally necessary in a rule-of-law system—the Tax Code also allows for changes when certain facts will have a favorable impact on the taxpayer.

The aim and purpose of this book is to present the relevant regulations. The individual provisions for the correction of tax assessments (Sections 129, 164, 165, 172 et seq. AO) are discussed chronologically according to their arrangement in the law. Numerous examples from case law will illustrate the conditions and legal consequences of the corrections in particular.