Payment rails
Push and pull rails
A push rail disburses on the sender’s instruction; a pull rail collects at the beneficiary’s request.
This distinction decides whether a service can pay you. SEPA transfer, PIX, NIP and ACH credit are push rails: the sender triggers, the beneficiary does nothing. Direct debit, cards, iDEAL and BLIK are pull rails: the merchant asks, the payer authorises.
A pull rail has no disbursement operation in its protocol. No commercial agreement creates a message that does not exist in the specification. That is why iDEAL, Bizum, BLIK, TWINT, Satispay and MB WAY appear in no serious payout catalogue — and, in Zelle’s case, because the network’s rulebook forbids third-party commercial use.