Errors in the Tax Return? Here’s How You Handle it Like a Pro

When signing your tax return, you pledge that all information provided by you is correct and complete. In other words, it’s mandatory by law that any incorrect information must be corrected, even after filing.


The first step is to find out precisely what information was incorrect or incomplete in both, your older and newer tax returns. Once you spot the error, it’s best to inform the tax office directly. This applies to errors that work in your favour or the other way round. As a rule, your tax official responds by setting a deadline for you to make the necessary correction.

Section 169 of the Tax Ordinance regulates the assessment period. For minor discrepancies and smaller amounts, you have a deadline of four years. If the tax office sees a ‘reckless tax evasion’ (leichtfertige Steuerverkürzung) leading to greater errors, there’s a time limit of five years. In the case of tax evasion, this period extends to 10 years.


However, this would mean that your mistake was on purpose, and you now want to make amends. Retroactive correction is possible as long as no tax audit prevents you from making a voluntary declaration without penalty. All deadlines begin with the year following the respective tax return. File error-free tax returns with Taxfix and eliminate tax anxiety. Start now.

If the mistake in your tax return is unfavourable to you, you have the right to a correction. Typically, this happens when invoices related to work or medical expenses arrive late.


You have four years to correct these errors, the prerequisite being that your missing information has not resulted from gross negligence (e.g. errors in bookkeeping).

There are four different ways to react to incorrect tax returns and tax assessment notices.

Correcting Errors Before Receiving the Tax Assessment Notice

Suppose you haven’t yet received the tax assessment. In that case, the correction is uncomplicated: You can contact your tax office clerk right away, and they can interrupt the processing of your tax return or postpone it until your correction is received. As a rule, you will be given a deadline and must submit the correction by then. You may do this through the form of a corrected tax return or informally without a form.

Appeal Against the Tax Assessment

What if you realise there are mistakes in your tax return only after reading the tax assessment? You receive four weeks to appeal against the tax assessment. The appeal includes a statement of reasons, best submitted with your corrections. If you cannot explain the tax assessment you have received, the tax office will recalculate the assessment.

Request for a Simple Amendment of the Tax Assessment Notice

Another possibility is to apply for a simple change of the tax assessment. In this case, you can informally apply for a reassessment within four weeks. The difference in appealing for a simple amendment is that only the corrected item is recalculated and not the entire tax return. This regulation is outlined in § 172 of the Tax Code. The advantage is that your situation can improve from this request. This procedure is often used when invoices relevant to your tax filing arrive late.

Withdrawal of the Tax Return

You also have the option of withdrawing your tax return. You will not receive a windfall — on the contrary, the tax office will demand an additional payment. After checking your tax assessment, if you believe that there is no mistake but that the tax office is correct, you can still withdraw your tax return by filing an objection.


The possibility of withdrawal only exists if the tax return is voluntary and is withdrawn within the deadline. If the tax office finds that you are obligated to file a tax return because, for example, you have additional income that you did not declare, your withdrawal does not count.

File error-free tax returns with Taxfix and eliminate tax anxiety. Start now.