Since you mention r-transactions (which is specific to SEPA): the SEPA rulebooks are surprisingly easy to read (e.g. for SCT[1]). For the US, NACHA maybe publis

Since you mention r-transactions (which is specific to SEPA): the SEPA rulebooks are surprisingly easy to read (e.g. for SCT[1]). For the US, NACHA maybe publishes similar specs? Neither are Swift though, for that perhaps https://www.swift.com/standards https://www.swift.com/standards is what you're looking for. How the actual settlement happens (e.g. RTGS/Target 2) is a bit more involved, and you won't find that in these rulebooks. [1] https://www.europeanpaymentscouncil.eu/what-we-do/epc-payment-schemes/sepa-credit-transfer/sepa-credit-transfer-rulebook-and https://www.europeanpaymentscouncil.eu/what-we-do/epc-paymen...