Banking103 · Module III · Lesson 08 of 9
Article · 12 min

Wires, ACH, and instant transfers

Which rail to use, and when.

Summary

For any transfer above a few hundred dollars, the Scholar should know which rail to use. Wires are irreversible and settle same-day. ACH is reversible for a short window and settles in one to three business days. RTP and FedNow are irreversible and settle in seconds but have low limits. The rail is a decision, not an afterthought.

Objectives
  • 01Distinguish the four major domestic transfer rails on speed, reversibility, and limit.
  • 02Choose the right rail for a specific transfer.
  • 03Explain why wires are the standard for real-estate closings.
The Lesson

The rails, tabulated

Wire: same-day, irreversible, high limits, $15–35 fee. ACH: 1–3 days, reversible for roughly 60 days for consumer errors, free or low-cost, per-transaction limits at most banks. RTP and FedNow: seconds, irreversible, typically $100,000 or lower, often free.

Choosing the rail

Large one-time transfer to a known counterparty with a firm deadline: wire. Recurring transfer or transfer to yourself: ACH. Real-time payment to a person you trust: RTP or FedNow. Real-estate closings are wire because the counterparty needs same-day confirmed funds and the parties are willing to trade reversibility for finality.

The fraud angle

Wires are the primary vector for high-value fraud precisely because they are irreversible. Every wire should be preceded by a voice call to the counterparty on a known number to confirm the account details. The most sophisticated fraud you will see is a spoofed wire instruction.

Key Ideas
  • Speed and reversibility are on opposite sides of a tradeoff.
  • Voice-confirm every high-value wire on a known number.
  • ACH is the workhorse. Wires are the exception.