Implementing KSeF: Checklist, Timeline

KSeF Timeline

Feburary 2026

mandatory for large enterprises (annual turnover exceeding PLN 200 million)

April 2026

mandatory for all remaining VAT taxpayers, including sole proprietors and SMEs

January 2027

mandatory for the smallest businesses (sales documented by invoices of up to PLN 10,000 per month)

How to Enhance Your KSeF Workflow

7 obszarów działania firmy z KSeF checklista

Verify Your Systems’ Compliance with KSeFReview your financial accounting system (ERP) and digital invoice workflow system. In many cases, integrating with a BPM (Business Process Management) system allows you to capture more data, which in the long run enables better financial reporting for your organization.
Apply for an Invoice Issuer CertificateIf you haven’t done it yet, apply to the Ministry for an invoice issuer certificate.
Choose How You’ll Handle e-Invoices
You can choose between:
- the Ministry of Finance portal,
- your ERP system,
- or an invoice workflow application integrated with KSeF via the GoNextStage KSeF Connector.
Get familiar with the FA(3) logical structure
FA(3) is the mandatory schema for structured invoices. Each field in your invoice must be properly tagged according to this schema.
The GoNextStage analytics team makes this easy: during the KSeF Connector implementation, you’ll receive a tool for mapping all fields together and later, seamlessly convert them into XML format.
Check If You Handle Invoice Attachments
If you receive invoices with attachments, make sure your system supports such documents. If you send invoices with attachments, you must obtain permission from the Tax Office by February to process these documents through KSeF.
Assign KSeF permissions to the people responsible for managing your company’s invoice workflow.
Test your invoice handling processes with KSeF
Issue test invoices through the National e-Invoicing System and verify that your systems correctly retrieve and archive documents.
Use professional support
If you’re looking to increase efficiency across invoice and finance processes, contact GoNextStage. Our consultants have supported organizations such as Canal+ Poland, GCity, and VINCI Construction in implementing process automation solutions that enhance operational performance and ensure compliance with European e-invoicing requirements.
Train your team on the new procedures and the implemented system.