Who has to comply with Poland's KSeF mandate first?

Businesses with a fixed establishment in Poland and turnover exceeding 200 million PLN, roughly 40 million pounds, must comply from 1 February 2026. The requirement then extends to most other VAT registered businesses from 1 April 2026, building on a voluntary B2B phase that has run since January 2022 and a B2G mandate in place since April 2019.

What format does KSeF require for Polish eInvoices?

Invoices must be submitted in the Faktura format, and attachments are not permitted. The KSeF system validates each submitted invoice and assigns it a unique ID number, which is what makes it a legally valid invoice. Businesses can submit either through an API connection or by manual upload into the system.

What are the penalties for non-compliance with KSeF?

Sanctions for non-compliance can reach up to 100% of the VAT due, or 18.7% of the total value of the invoice. Managing high volumes of invoice data and corrections manually in-house also carries operational risk, which is why businesses are advised to favour a reliable automated submission process over a manual one.

How long must Polish businesses keep eInvoice records?

Businesses affected by the KSeF mandate must hold an electronic archive of their invoice records for 10 years. This applies alongside the submission requirements, whether invoices are sent via API connection or manual upload, and is part of the wider Continuous Transaction Controls framework KSeF operates under.

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Poland eInvoice regulations

Poland eInvoice requirements for B2B transactions are mandated from 2026. Learn which businesses are affected, the submission requirements, and automation solutions available.

Transalis18 January 2024Updated 23 September 2026

Key takeaways

Poland's KSeF system moves B2B invoicing to real time government reporting, with the largest taxpayers, turnover above 200 million PLN, required to comply from 1 February 2026.
The KSeF requirement then expands to most other VAT registered businesses in Poland from 1 April 2026, following a voluntary B2B phase that began in January 2022.
B2G invoicing in Poland has been mandatory since April 2019, giving businesses a longer runway of experience with structured electronic invoicing ahead of the new B2B rollout.
Invoices must be submitted in the Faktura format with no attachments, and KSeF validates each one and assigns a unique ID before it becomes legally valid.
Businesses can submit invoices via API or manual upload, must keep an electronic archive of records for 10 years, and face sanctions up to 100% of VAT due.

What is Poland's KSeF eInvoicing mandate?

KSeF, or Krajowy System e-Faktur, is Poland's mandatory B2B eInvoicing and real time reporting system. The largest taxpayers, those with turnover above 200 million PLN, must comply from 1 February 2026, with the requirement extending to most other VAT registered businesses from 1 April 2026. Invoices must be submitted in the Faktura format via API or manual upload, and records must be archived for 10 years.

New Poland eInvoice regulations are due to come into effect from 1st February 2026. Businesses with a fixed establishment in the country will need to ensure their compliance.

Following a voluntary phase which started in 2022 for B2B transactions, the Polish authorities plan to introduce mandatory B2B invoice reporting via their online system, Krajowy System e-Faktur (KSeF).

Remove the complexities of compliance

Schedule a meeting with our knowledgeable eInvoice compliance team to discuss our packaged automation solutions that simplify compliance for your business

In this blog, we outline the requirements applicable to those operating in Poland and how we can help businesses meet this new eInvoice mandate.

Summary of Poland eInvoice deadlines

Poland has been phasing in eInvoice regulations for several years, similar to many other European countries.

Below is a summary of the existing and upcoming eInvoice and tax reporting deadlines for businesses with a fixed establishment in Poland:

B2G transactions mandated since April 2019
A voluntary phase for B2B transactions introduced in January 2022
B2B entities with a turnover exceeding 200 million PLN (approx £40 million/$50 million) mandated from 1st February 2026 for
The requirement expands to all others from 1st April 2026.

Submission and reporting requirements

New eInvoice mandates often mean new operational complexities.

Polish eInvoicing regulations follow a Continuous Transaction Controls (CTCs) framework, which mandates the real-time reporting of financial data to the tax authority. This information must be reported using an approved method in the permitted format via the Polish online system called Krajowy System e-Faktur (KSeF).

The new system requires all invoices to be submitted using ‘Faktura’ format and attachments are not permitted. The KSeF system validates the invoices submitted and assigns a unique ID number, making it a legally valid invoice. Businesses ultimately have two choices when it comes to submission, an API connection or manual upload. Businesses also must ensure they hold an electronic archive of invoice records for 10 years.

For any business required to meet this new mandate, it can be overwhelming when considering how these new invoice processing requirements can be fulfilled.

For example, those considering a ‘no-cost’ route and managing the compliance requirements in-house via a manual reporting process, will experience challenges with high volumes of invoice data and any corrections. This could also become a costly route as there will be sanctions for non-compliance. These sanctions can include fines of up to 100% of the VAT due, or 18.7% of the total value of the invoice.

Automating compliance

Businesses affected by the new Polish requirements should favour a reliable solution that removes this compliance headache.

Transalis has experience implementing automated compliance solutions for its clients per requirements across Europe. Our focus when supporting our clients always revolves around ensuring simplicity and transparency. Implementing an eInvoice solution provides peace of mind for our clients regarding ensuring compliance with requirements. We also offer transparently priced packaged solutions, there are no hidden fees and no escalating costs.

Compliance with Poland eInvoicing regulations using our solutions offers all the functionality required. This includes API connectivity, CTCs, system integration, and archiving. Transalis offers the opportunity for businesses affected by this new mandate to eliminate the headache of managing compliance in-house.

We also recommend the strategic use of document transformation solutions to offset the cost of compliance. Typically, an extortionate amount of time is spent on manual document processing within the Accounts Payable team. For example, rekeying invoice data from PDF files into the finance management system. This inefficiency can be eliminated through the use of an Inbound invoice automation solution that captures inbound documents, extracts the relevant data, and adds it to the relevant system for approval.

This approach can provide 60-80% savings over manual processes, allowing for budget to be reallocated to support the onboarding of automated solutions for eInvoice compliance. Take a look at our eInvoice solutions below for more information:

Frequently asked questions

Who has to comply with Poland's KSeF mandate first?: Businesses with a fixed establishment in Poland and turnover exceeding 200 million PLN, roughly 40 million pounds, must comply from 1 February 2026. The requirement then extends to most other VAT registered businesses from 1 April 2026, building on a voluntary B2B phase that has run since January 2022 and a B2G mandate in place since April 2019.
What format does KSeF require for Polish eInvoices?: Invoices must be submitted in the Faktura format, and attachments are not permitted. The KSeF system validates each submitted invoice and assigns it a unique ID number, which is what makes it a legally valid invoice. Businesses can submit either through an API connection or by manual upload into the system.
What are the penalties for non-compliance with KSeF?: Sanctions for non-compliance can reach up to 100% of the VAT due, or 18.7% of the total value of the invoice. Managing high volumes of invoice data and corrections manually in-house also carries operational risk, which is why businesses are advised to favour a reliable automated submission process over a manual one.
How long must Polish businesses keep eInvoice records?: Businesses affected by the KSeF mandate must hold an electronic archive of their invoice records for 10 years. This applies alongside the submission requirements, whether invoices are sent via API connection or manual upload, and is part of the wider Continuous Transaction Controls framework KSeF operates under.

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