KSeF number in the transfer: new obligation from 2027
From January 1, 2027, when paying for e-invoices, you will be required to provide your KSeF (National e-Invoicing System) number or collective identification number. This requirement will apply to payments that meet the conditions described below.
What will you learn from this text?
- from when will the KSeF number or collective identifier have to be provided when paying for e-invoices;
- when the obligation to indicate the KSeF number in the transfer will apply and when it will not;
- what identifier to use when paying for a single invoice and which one for a bulk payment;
- how the new rules will affect the split payment mechanism (MPP);
- how to prepare your ERP system, banking and payment procedures before January 1, 2027
When will the KSeF number be required?
From 1 January 2027, the number will have to be provided if all of the following conditions are met:
- the payer is the buyer registered as an active VAT payer;
- the recipient of the payment is also an active VAT payer; recipient status is determined on the date of payment based on the list of VAT payers;
- the payment concerns a structured invoice or an invoice issued offline24 or during KSeF unavailability;
- payment is made by transfer or other payment instrument allowing the purpose of the funds transfer to be indicated.
The number will also be required by taxpayers paying for invoices issued to other entities, for example, in certain payment or financing centralization models. In the case of direct debits, this obligation will rest with the invoice issuer.
The new rules will not apply to, among other things, payments to VAT-exempt taxpayers or settlements made using a method that does not allow for the transfer purpose to be specified. An exception is also provided for offline invoices that were not entered into the KSeF due to an official outage. These invoices do not have a KSeF number, so it is not necessary to provide one when making a payment.
One invoice or bulk payment?
When paying for a single invoice, you must provide its 35-character KSeF number, not the number assigned by the seller. KSeF assigns this number automatically upon receipt of the invoice. Example:
5265877635-20250826-0100001AF629-AF
Example transfer title:
Invoice payment – KSeF 5265877635-20250826-0100001AF629-AF
In the split payment mechanism (MPP), the KSeF number will need to be entered in the transfer message field intended for the invoice number.
When paying for more than one invoice from a single seller, you must provide a collective identifier assigned by the KSeF. This is generated for a list of at least two KSeF numbers and then entered in the transfer. The official identifier template:
9999999999-IZ202701-FFFFFFFFFFFF-FF
When making bulk payments for e-invoices in the split payment method, the collective identifier will replace the previously specified period. Payments for structured invoices will be able to cover selected invoices from a single supplier, with a period ranging from one day to one month.
According to the Ministry of Finance, the identifier can be generated and read using KSeF tools or financial and accounting systems connected to the KSeF API. The Ministry of Finance's IT Centre roadmap indicates that this feature has already been implemented in the production version of the API. However, software vendors continue to report integration issues.
What should companies prepare?
Preparations require verifying that data from the KSeF is transferred to the financial and accounting system (ERP) and then to the banking system. By the end of 2026, it is worth:
- ensure that the KSeF number is recorded with each purchase invoice;
- ensure verification of the recipient's VAT status on the date of payment;
- adapt transfer batches and MPP messages to transmit the KSeF number or collective identifier;
- implement the generation and decoding of collective identifiers;
- describe the handling of partial payments, direct debits, payments made by third parties and offline invoices.
Manually entering 35-character numbers increases the risk of errors and misallocations, and subsequent reconciliation requires additional work. Processing of incoming bulk transfers also requires preparation: the recipient must read the identifier and determine which invoices the payment relates to.
Expert commentary
The requirement to provide the KSeF number in payments doesn't end with changing the transfer purpose. In practice, companies should ensure a consistent flow of data from the KSeF, through the financial and accounting system, to the payment process. The fewer manual operations, the lower the risk of errors and subsequent problems with reconciliation.
Szymon Lipiński, Senior Tax Consultant, Crowe Poland
FAQ: KSeF number in transfer from 2027
From 1 January 2027, the KSeF number or collective identification number will have to be indicated for payments that meet the conditions described in the regulations, including payments for structured invoices made between active VAT payers.
No. The obligation will apply to payments that meet certain cumulative conditions. It will not apply to, among other things, payments to VAT-exempt taxpayers or settlements made using a method that does not allow for the transfer title to be disclosed.
When paying for a single invoice, please provide its 35-character KSeF number assigned automatically after the invoice is accepted by the system, and not the invoice number assigned by the seller.
When paying for two or more invoices from one seller, use the collective identifier generated for the indicated list of KSeF numbers.
When paying for a single invoice, the KSeF number will need to be entered in the invoice number field of the transfer message. For bulk payments for e-invoices, the bulk identifier will replace the period previously indicated.
First of all, it is worth ensuring that the KSeF number is saved with purchase invoices, the recipient's VAT status is verified on the payment date, the KSeF number or collective identifier is transferred to transfer batches, and partial payments, direct debits, payments by third parties and offline invoices are handled.
How can we help?
Preparing for the new KSeF payment rules requires a combination of tax, process, and technology perspectives. Crowe Poland experts support companies at every stage of KSeF implementation, from readiness analysis and process audits, through data mapping and defining technical requirements, to procedure preparation and implementation support.
In the context of the KSeF number in transfers, we can help analyse the flow of purchase invoices and the payment process, identify areas requiring adjustments to financial and accounting systems, streamline the rules for handling authorizations, adjustments, and emergency situations, and prepare finance, accounting, and IT teams for their new responsibilities. Crowe also offers training and workshops, as well as ongoing expert support through the KSeF hotline.
If you want to check whether the processes and systems in your organization are ready for the obligation to provide the KSeF number in payments from 2027, please write to us.
