Since 1 January 2021 the First Mazowiecki Tax Office (Pierwszy Mazowiecki Urząd Skarbowy, or 1MUS) in Warsaw has been appointed as a specialised tax office serving the largest taxpayers. The scope of this jurisdiction will change after the publication of a new regulation by the Minister for Finance and Economy on 20 August 2025. The most important of the changes are described below:

  • The revenue threshold making taxpayers subject to 1MUS jurisdiction will go up from EUR 50 million to EUR 100 million as of 1 January 2026.
    • Those taxpayers served by 1MUS who met the previous threshold but not the new one may choose to transfer to a different tax office on condition that they submit such a request to 1MUS by 15 October 2025 and did not exceed the threshold in 2023 or 2024.
    • You will not fall out of a taxpayer category unless and until you fail to meet the revenue test for two subsequent tax years.
    • To see whether or not you will be excluded from your category as of 1 January 2026, you need to take into account your revenue for 2023 and 2024 or, where your tax year is not the same as calendar year, for two most recent tax years the last of which ended no later than in 2024.
  • Change in the EUR to PLN translation method: instead of the rate ruling on the last date of the tax year, you need to use the one ruling on the last business day of the tax year.
  • More taxpayer groups served by 1MUS: the category of taxpayers and withholding agents of significant economic or social importance, which is served by specialised tax offices such as 1MUS, will extend onto entities that are parties to cooperative compliance agreements with the Polish National Revenue Administration (Szef KAS).

If this issue pertains to your business and you are interested in our assistance, please contact us.

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