Are you talking about SCT Inst? It seems like there are no fees built into the protocol itself, but your bank can still charge you to use the service, and it seems many banks charge between 1 and 7 euros:
I didn’t mean a specific protocol, just based on my experience. But where do you see 7€ in this document? I see lot of banks offering zero or below 1€ fees. The highest I see is Novo Banco at 5.20€ (page 18).
Besides SEPA which mandated the upper ceiling and an upcoming regulation which forbids banks from de-prioritising payments to/from other banks (can't remember what it's called now) many European countries have had instant bank transfers locally. For example, Swish in Sweden: https://www.swish.nu/about-swish
