After the corporation tax return has been submitted to the responsible tax office, it is checked by the tax office.

After the audit, the tax office will issue a corporation tax assessment. This is used to determine corporation tax.

In principle, the corporation tax return must be submitted by:

• 31 July of the calendar year following the tax period if you are not advised on tax matters
• 28 or 29 February of the second calendar year following the tax period if you are advised on tax matters

The deadline for submitting tax returns for advised taxpayers, which generally expires on 28 February 2021 for the calendar year 2019, has been extended by law by 6 months (for advised farmers and foresters with a different marketing year, the submission deadline, which generally expires on 31 July 2021, has been extended by 5 months). Tax returns for 2019 can therefore be submitted in consultation cases by the deadline of 31 August 2021 (for advised farmers and foresters with a different marketing year until 31 December 2021).

For the 2020 assessment period, the deadline for submitting tax returns has generally been extended by three months for all advised and non-advised taxpayers. Taxpayers who prepare their returns themselves can therefore submit their tax returns within the deadline of 31 October 2021 (for farmers and foresters, by the end of the tenth month following the end of the fiscal year beginning in calendar year 2020). Advised taxpayers can submit the returns in due time until 31 May 2022 (for advised farmers and foresters with a different marketing year until 31 October 2022).

These extended return periods do not apply to tax returns that must be submitted at an earlier date on the basis of a separate order ("preliminary request").

How long it takes to process a corporate income tax return or to assess corporation tax always depends on the circumstances of the individual case.