ecosio's Global E‑invoicing Compliance solution is production‑ready for Poland's KSeF mandate. With country‑specific support for FA(3) and the KSeF 2.0 API, you can move from planning to implementation with confidence ahead of the 2026 rollout.

What's changing in Poland

Poland is adopting a centralised, clearance‑style model via KSeF. Invoices are submitted to KSeF, validated, timestamped and assigned a legal KSeF ID before being made available to buyers. FA(3) is the structured invoice format used under KSeF 2.0.

Key dates:

• 1 January 2026: Taxpayers can submit notifications to issue invoices with attachments.

• 1 February 2026: Mandatory for taxpayers with revenue over PLN 200m. Main regulation enters into force, aligned with KSeF 2.0 go-live. PEF (Platforma Elektronicznego Fakturowania) will be merged with KSeF, and for B2G invoices businesses may be able to use either KSeF or PEF.

• 31 March 2026: Last day to use the Trusted Profile for KSeF authentication.

• 1 April 2026: Mandatory for all other VAT-registered taxpayers. National node authentication becomes available and VAT RR provisions take effect.

• 1 January 2027: Tokens can no longer be used for KSeF authentication.

B2G flows run through KSeF under the new framework. In some cases, a PEF can still be used to report invoices to KSeF on your behalf. KSeF handles legal archiving for 10 year, and external archiving is permitted.

What this means for you

• Full alignment with Poland's FA(3) schema and validation logic, with proactive updates as guidance evolves

• End‑to‑end visibility over outbound and inbound documents, including KSeF IDs and statuses, via a central dashboard

• Secure API connectivity to KSeF and flexible ERP integration patterns

• Country‑specific onboarding for registration, credentials and role delegation, plus managed exception handling and SLAs

The value of ecosio's Poland coverage

• Transformation to FA(3) across standard, correction, advance and margin invoices so you run one mapping for all scenarios, cutting maintenance, speeding onboarding and reducing failed submissions.

• Automated submission, response handling and KSeF ID correlation to shorten cycle times and manual work while ensuring every transaction carries a legal ID for audit-readiness and faster dispute resolution.

• Inbound retrieval and delivery to your ERP with optional PDF visualisation so AP posts only legally valid invoices in familiar views, reducing exceptions and rework.

• Monitoring tuned to KSeF validations with transparent status tracking to detect errors early, resolve faster, protect cash flow and improve SLA adherence.

Why act now

With phased go‑lives in early 2026 and penalties starting in 2027, organisations need time for design, mapping, testing and a controlled rollout. Our Poland country pack and onboarding playbook de‑risk timelines and accelerate go‑live.

Ready to get started?

Plan your path to KSeF with ecosio. Explore the details and contact our team via the Poland country page: https://ecosio.com/en/compliance/poland/e-invoicing/

The ecosio Product Team