Perspectives · Poland
KSeF makes invoice authority an entity-governance question
Poland's mandatory KSeF rollout began on 1 February 2026 for taxpayers whose 2024 sales including VAT exceeded PLN 200 million and on 1 April 2026 for most remaining taxpayers. Receipt through KSeF has been mandatory from 1 February, subject to statutory exceptions, while the smallest issuers have a limited PLN 10,000 monthly transition through the end of 2026. The system change is also a change in corporate authority. This perspective is general information, not Polish tax or legal advice.
The mandate
Two dates, one portfolio operating model
The phased dates can make KSeF look like a threshold exercise. For a group, the harder task is identifying every Polish VAT registration and entity that must issue, receive or support structured invoices, then assigning a working owner before the date applies.
The receiving obligation is especially easy to miss. Even where an entity benefits from a temporary issuing exception, its accounts-payable process may already need to retrieve invoices from KSeF. The portfolio view must therefore separate issuing scope, receiving scope and statutory exclusions rather than attaching one generic "KSeF ready" flag to every company.
The authority
Who can act for each taxpayer becomes a governed record
KSeF permissions determine who or which system can issue, access and manage invoices for a taxpayer. Certificates and authorisations are not simply IT credentials; they express who is allowed to act for a legal entity and through which software or service provider.
That authority changes when employees leave, accountants change, directors rotate or a shared-service centre is reorganised. Certificates can expire, and offline processes require the correct certificate to exist before an outage. A one-off implementation spreadsheet will age quickly unless role changes and renewals feed the same control.
The master data
Invoice integrity starts with entity identity
A structured invoice can only be as reliable as the entity data feeding it. Legal name, NIP, VAT status, address, bank data, customer and supplier identifiers and the relationship between branch and legal entity need a controlled source.
This is where tax implementation meets entity management. A merger, liquidation, name change or VAT deregistration is not only a company-secretarial event. It can change which taxpayer is entitled to issue or receive an invoice, which credentials remain valid and which system mapping must be updated.
The outage
Offline24 still needs an owner and an evidence trail
KSeF's offline24 route supports invoicing during temporary unavailability, but it does not remove control. The correct certificate must be used, the invoice must carry the required verification data, and the record must be transmitted within the applicable deadline, generally by the next working day.
Groups should pre-agree who declares an outage, who approves use of the fallback, how duplicate transmission is prevented and where the later KSeF identifier is reconciled. An emergency process that exists only in a vendor manual is not an operating control.
In Alethia
Govern the entity around the invoice engine
Alethia is not an invoicing platform and should not replace KSeF-connected accounting software. It can hold the portfolio control around that software: which entities are in scope, their identifiers, the responsible owner, service provider, permissions, certificate renewal, transition status, documents and evidence.
That matters most when the portfolio changes. If an entity is acquired, renamed, merged, put into liquidation or handed to a new administrator, the KSeF work can follow the same entity event instead of waiting for an invoice to fail.
Questions
Mandatory KSeF in 2026, answered
Who had to issue through KSeF from 1 February 2026?
Taxpayers whose 2024 sales including VAT exceeded PLN 200 million. Most other taxpayers moved to mandatory issuing from 1 April 2026, subject to statutory exclusions and the limited small-issuer transition through 31 December 2026.
When did mandatory receipt begin?
The Ministry of Finance states that taxpayers have been required to receive KSeF invoices from 1 February 2026, apart from cases excluded by law or where a transitional paper or electronic invoice remains permitted.
Does the 2026 penalty transition mean a company can wait?
No. Transitional relief around penalties or small issuers does not remove the underlying need to determine scope, establish permissions and ensure that receiving and issuing processes work. Local advice should confirm the exact position.
Know who can invoice for every Polish entity
Connect taxpayer scope, permissions, certificates, service providers and entity changes before KSeF turns a stale record into a failed process.