Poland mandates JPK services interface specification v5.5.0 from 16 June 2026
Poland's Ministry of Finance published JPK services interface v5.5.0 on 11 June 2026, effective 16 June 2026. Software vendors and taxpayers have a 5-day window to update integrations before the new specification becomes binding.
Poland’s Ministry of Finance published version 5.5.0 of the JPK services interface specification on 11 June 2026, with mandatory compliance from 16 June 2026. The 5-day transition window applies to all filers: individuals, sole traders, SMEs, withholding agents, and companies.
Poland’s Ministry of Finance published version 5.5.0 of the JPK services interface specification on 11 June 2026. The new specification becomes binding on 16 June 2026, giving software providers and taxpayers only a five-day window to align their integrations.
The JPK (Jednolity Plik Kontrolny, also known as SAF-T) is the technical interface used by taxpayers and software vendors to submit tax files to Polish tax authorities. The specification defines the schemas, endpoints, and authentication flows required for these submissions.
Who is affected
The update applies to all categories of filers:
- Natural persons (Osoba fizyczna)
- Sole traders (Jednoosobowa działalność gospodarcza)
- Small and medium enterprises (Mały i średni przedsiębiorca)
- Withholding agents (Płatnik)
- Companies and organisations (Spółki i organizacje)
All JPK-using taxpayers and their software integrators must comply by the deadline.
What to do
Tax teams and IT integrators should verify that schemas, endpoints, and authentication flows in their middleware are updated by 16 June 2026. This includes any KSeF/JPK gateways or related systems. Failure to update before the deadline risks rejected submissions.
This update is part of Poland’s broader iteration of its JPK ecosystem, which runs alongside the KSeF e-invoicing rollout. KSeF mandatory phases began in February 2026 for large taxpayers and continue to expand.