Seriál Dodatečné daňové přiznání: Kdy vzniká povinnost ho podat?

Series Supplementary tax return: when does the obligation to file arise?

In the life of taxpayers, there are times when the obligation to file a supplementary tax return arises. The most common situations we encounter in practice are situations such as the completion of a statutory audit after the deadline for filing a tax return or, for example, forgotten expenses or revenues. Less frequent are situations where tax losses are carried back or tax depreciation is retrospectively interrupted.

In our next series focused on supplementary tax returns, we will go through when the obligation to file supplementary tax returns arises, as well as related penalties and ways to reduce them, and tips and tricks from practice.

Obligation to file supplementary tax returns

Pursuant to Section 141(1) of the Tax Code, a taxpayer is obliged to file a supplementary tax return if he discovers that the newly calculated tax is to be higher than the last known tax liability, i.e. the tax that had already been assessed by the tax administrator, for example in the ordinary tax return.

Example: A company booked a forgotten revenue in 2023 for products sold in 2022, this revenue was not included in the ordinary tax return for 2022. Its non-inclusion has resulted in an incorrect calculation of a lower tax liability in the ordinary tax return for 2022. The taxpayer is therefore obliged to file a supplementary tax return for 2022 and to tax the forgotten revenue.

If the newly calculated tax is to be lower than the last known tax liability, the taxpayer has the option to file a supplementary tax return (Section 141(2) of the Tax Code). The taxpayer also has the option to file a supplementary return if the filing of the supplementary return does not change the last known tax liability but only changes the previously claimed data (Section 141(4) of the Tax Code).

Example: A company has identified that it booked a forgotten expense in 2023 that relates to 2022, and this expense was not included in the ordinary tax return for 2022. Therefore, it is an expense of 2022 and its non-inclusion has resulted in a calculation of a higher tax liability in the ordinary return. The taxpayer is therefore able to file a supplementary tax return for 2022, treat the expense as tax deductible and claim back the tax paid.

Deadline for filing a supplementary tax return

The deadline for filing a supplementary return is the end of the month following the month in which the taxpayer becomes aware of the obligation to file. The additional tax is due within the same period.

Example: The taxpayer discovered on 15 May 2023 that he booked a revenue in 2023 that relates to 2022. He must file a supplementary tax return by 30 June 2023. He must also pay the difference in tax by that date.

When the taxpayer files a supplementary tax return for a lower tax liability, the deadline for filing is generally as long as the period for determining the tax, i.e. generally three years, see decision 2 Afs 363/2019-50. Alternatively, see our alert HERE.

The obligation or option to file a supplementary tax return lasts as long as the period for tax assessment is running. Generally, the period is 3 years and starts on the date on which the deadline for filing the ordinary tax return expired. However, this period may be extended for various reasons (e.g. by filing a supplementary tax return in the last 12 months before the expiry of the existing period, by the assessment of a tax loss or by the granting of an investment incentive in the form of a tax credit, etc.).

Contact your tax adviser or the authors of this article if you find out that you are obliged to file a supplementary tax return. We will be happy to discuss all the options with you.

Authors:

Barbora Výšková
Barbora Ptošková
Lam Uyen Le