KSeF 2.0 changes more than the file format of a Polish invoice. It changes when an invoice is legally issued and received, who may access it, how a rejected file is handled, how a foreign customer receives a visualisation and what the company must do when the system or its own Internet connection is unavailable. A correct implementation therefore joins tax analysis, accounting, sales, payments, access security and IT.
1. What KSeF 2.0 does — and what it does not do
KSeF is the state system for issuing, sending, receiving, accessing and storing structured invoices and for managing permissions. The legal invoice is the XML file compliant with the FA(3) logical structure after the system accepts it and assigns a unique KSeF number. A PDF is only a human-readable visualisation. KSeF does not decide whether the transaction is real, whether the VAT rate or place of supply is correct, or whether the buyer may deduct input VAT.
| Business event | sales/accounting data are approved |
|---|---|
| Generation | accounting or invoicing software creates FA(3) XML |
| Transmission | XML is sent online or under an applicable offline procedure |
| Validation | KSeF accepts or rejects the file |
| Legal evidence | accepted invoice receives a KSeF number; retain status/UPO and operational logs |
| Accounting | sale, purchase, payment and JPK records are reconciled |
2. Who must issue invoices in KSeF?
| From 1 February 2026 | taxpayers with 2024 gross sales above PLN 200 million |
|---|---|
| From 1 April 2026 | most other active and VAT-exempt taxpayers |
| Until 31 December 2026 | invoices may remain outside KSeF where monthly gross sales documented by invoices subject to KSeF are no more than PLN 10,000 |
| From 1 January 2027 | the transitional PLN 10,000 relief ends; KSeF penalties and payment-reference duties apply under the statutory rules |
Domestic VAT exemption does not by itself remove the KSeF obligation. A taxpayer exempt under the domestic small-business rules is generally within KSeF, subject to the transitional PLN 10,000 rule and statutory exclusions. By contrast, invoices documenting activities covered by the cross-border SME exemption under Article 113a are outside KSeF. Consumer invoices may be issued in KSeF voluntarily.
3. Foreign businesses, consumers and transactions outside the mandatory scope
A foreign taxpayer without a seat or fixed establishment in Poland is not required to issue through KSeF. The same exclusion applies where a foreign taxpayer has a Polish fixed establishment but that establishment does not participate in the supply. Other exclusions include selected special procedures and specified documents or self-billing cases. An excluded taxpayer may sometimes use KSeF voluntarily, but not every statutory exclusion permits voluntary use. The transaction and the parties’ identifiers must therefore be classified before the invoice channel is chosen.
Where the buyer is a consumer, a foreign entity or another person covered by the statutory outside-KSeF delivery rules, the seller must provide the invoice in an agreed manner, for example as a compliant visualisation with the required QR code. For a domestic business identified by Polish NIP, no buyer acceptance is needed: the invoice is received through KSeF when the system assigns its number.
4. The online invoice flow and the legally relevant dates
- Approve master data, VAT classification, price, bank account and recipient identifiers.
- Generate the FA(3) XML in an integrated system or an MF application.
- Authenticate in the correct taxpayer context and send the file.
- Monitor the processing status; a generated PDF is not proof that KSeF accepted the invoice.
- Save the KSeF number and status/UPO in the sales ledger and link them to the commercial document.
- Deliver a visualisation outside KSeF only where the law requires or permits it.
In online mode an invoice is issued on the day it is sent to KSeF, provided it is transmitted on the date stated in field P_1. It is received by a domestic VAT taxpayer when the KSeF number is assigned. If the file is sent later than the P_1 date, the invoice is treated under offline24 rules. A rejection means that no structured invoice has been issued; the cause must be corrected and the file sent again under the applicable procedure.
5. Permissions: the company, employees and the accounting office
| Taxpayer/owner | obtains the primary entitlement and decides who may act |
|---|---|
| KSeF administrator | manages entitlements; should not automatically receive every operational right |
| Sales user/system | may issue invoices only in the assigned taxpayer context |
| Accounting office | needs separately delegated rights for each client context to issue and/or view invoices |
| Reviewer/finance | may view invoices and reconcile status, payment and accounting records |
| IT/integrator | should receive only the technical access required for the integration |
A sole trader normally has the primary entitlement assigned automatically to the business NIP. A company can authenticate with a qualified electronic seal or appoint an authorised person through ZAW-FA when the statutory conditions require it. An accounting office does not automatically see every client’s invoices: it must authenticate in each client’s NIP context and hold the rights granted by that client. Access must be withdrawn immediately when an employee, adviser or provider changes role.
6. Certificates, tokens and security
A type 1 KSeF certificate is used as an authentication method. A type 2 certificate is required to generate the issuer-verification code for invoices created under offline24, planned unavailability or emergency procedures. A certificate is valid for no more than two years. Tokens and certificates may coexist until the end of 2026, but from 1 January 2027 certificates remain the target solution. Certificates, tokens and private keys must not be shared through email or stored in an unprotected folder; ownership, renewal, revocation and incident response should be documented.
7. Online, offline24, unavailability, emergency and total failure
| Online | send on the P_1 date | invoice issued on transmission; buyer receives it when KSeF number is assigned |
|---|---|---|
| Offline24 | may be chosen, e.g. for the taxpayer’s connectivity problem | send no later than the next working day after issue |
| Offline — KSeF unavailable | use during planned unavailability announced by MF | send no later than the next working day after the unavailability ends |
| Emergency | use during an outage announced in MF BIP and the interface | send within 7 working days after the outage ends |
| Total failure | announced through mass media | invoices are issued outside the system and are not later sent to KSeF |
Offline invoices use FA(3) and, where delivered outside KSeF before they receive a number, require the prescribed OFFLINE and CERTIFICATE QR codes; the second code requires a type 2 certificate. The company should document who monitors MF notices, who activates each procedure, who sends the backlog and who verifies acceptance after service is restored. A general instruction to ‘send later’ is not enough.
8. Corrections, attachments and documents that do not enter KSeF
A correction to a structured invoice identifies the original KSeF number. If the original was created offline and has not yet been accepted, it must first be sent and assigned a KSeF number before the correction is issued. From 1 February 2026 correcting notes no longer operate. Pro formas, internal documents, credit notes and debit notes are not sent to KSeF. A structured invoice may contain an integrated attachment only after the taxpayer submits the dedicated ZGL_ZAL notification in e-Urząd Skarbowy; the attachment may contain invoice-related data, not marketing material.
9. KSeF does not transfer the company’s responsibility to the accounting office
| Company/management | determines the transaction, customer, price, performance date, approval and authorised users |
|---|---|
| Sales/operations | provides complete source data and verifies recipient identifiers before issue |
| Accounting office | configures agreed accounting rules, may issue/download under delegated rights, books accepted invoices and reconciles registers |
| IT provider | maintains integration, certificates, queues, logs and fallback procedures |
| Joint control | rejected files, duplicate business events, foreign delivery, corrections, payment matching and access reviews |
Granting an accountant permission to issue invoices is not the same as transferring tax responsibility. The company must still provide correct commercial data and approve the business event. The accounting office should define the cut-off, accepted communication channel, rejection report, correction workflow and the evidence returned to the client. Emergency access should be tested before it is needed.
10. JPK, payments and document reconciliation
From 1 February 2026 the JPK_V7M(3) and JPK_V7K(3) records include the KSeF invoice number for sales and purchases where applicable. From 1 January 2027 active VAT taxpayers making qualifying transfers for structured and specified offline invoices must state the KSeF number or a collective identifier, including in the split-payment mechanism. The invoice register, KSeF download, bank statement and accounting ledger must therefore use the same identifiers. KSeF storage does not replace retention of contracts, approvals, delivery evidence or tax analysis.
11. Common implementation errors
- treating the PDF visualisation as the legal source and ignoring the XML/status;
- granting one shared access credential to several people;
- assuming the accounting office receives rights automatically;
- sending a foreign or consumer invoice without the required agreed delivery and QR process;
- using offline24 without monitoring the next-working-day deadline;
- creating a correction before the offline original receives a KSeF number;
- failing to reconcile rejected files, KSeF numbers, JPK and bank payments;
- applying the PLN 10,000 relief as an annual turnover exemption.
12. KSeF implementation checklist
- Map sales and purchase invoice types, foreign flows, consumer invoices and exclusions.
- Identify every system and person that creates, approves, sends, receives or books an invoice.
- Assign least-privilege rights and document ZAW-FA/seal decisions.
- Obtain and securely manage the required certificates; plan token retirement before 2027.
- Validate FA(3), buyer identifiers, corrections, QR visualisations and rejection handling.
- Write separate procedures for offline24, planned unavailability, emergency and total failure.
- Integrate KSeF numbers with sales, purchases, JPK and payments.
- Agree the division of work and evidence exchange with the accounting office.
- Test access removal, certificate expiry, backlog sending and management reporting.
- Recheck law, MF notices and software configuration after every material change.
inPL can coordinate accounting, business process outsourcing and IT services for the KSeF workflow, including access, document exchange, accounting controls and integration requirements.
Information verified on 20 August 2026. KSeF treatment depends on the taxpayer, transaction, recipient and applicable procedure. Recheck the VAT Act, regulations, MF notices, FA schema and software documentation before implementation.