The European Payments Council has published version 4.0 of the Single Euro Payments Area Request-to-Pay Implementation Guidelines, setting out how to implement the relevant ISO 20022 XML message standards under version 4.0 of the SEPA Request-to-Pay scheme rulebook. The related rulebook version takes effect on 5 October 2025 at 03:30 CEST. The update comprises three version 4.0 guideline documents covering message flows in both directions for the payee to payee’s RTP Service Provider space, the inter-RTP Service Provider space, and the payer to payer’s RTP Service Provider space (documents EPC258-22, EPC259-22 and EPC260-22). Section 4 of each document summarises changes from version 3.0, and the EPC has also made available the associated SEPA XML Schema Definitions for the SRTP guidelines. The SRTP inter-PSP API specifications are expected to be published in due course.