| TLDR: Nearly all payments will irrefutably settle within a handful of seconds Strictly speaking the primary means in which money moves in the United States from a volume perspective is ACH today. That system is a T+1 day from a default perspective, but it has offered the option to same-day settle during a handful of batches throughout a business day. However, ACH is not irrefutable and so it is common to have holds associated with this movement of money. FedNow is truly 24/7/365 and push only. All payment flows are subject to an end-to-end payment timeout clock of 20 seconds, starting from the creation timestamp to the point at which the recipient FI (almost always really a Service Provider on their behalf) sends a formal response that they intend to accept or reject the message. An accepted payment must then be posted to the receiving account "as soon as practicable, but no longer than a few seconds” unless there are compliance/fraud concerns. In practice, it should rarely take 23 seconds and will likely take 1-5 seconds from an end-to-end perspective depending on the processing speed of the originator, receiver and FedNow Service itself. |