FedNow API

A FedNow API is a programming interface through which a bank, credit union, fintech or business sends and receives instant payments over FedNow, the US instant payment service run by the Federal Reserve Banks. The phrase is practitioner shorthand rather than the name of an official product: the Federal Reserve does not publish a public web API for FedNow. Participating institutions connect through the Fed's FedLine network and exchange ISO 20022 messages; the "FedNow APIs" that developers use are interfaces built by banks, core banking vendors and service providers that translate simple API calls into those messages.

FedNow went live in July 2023. It runs 24 hours a day, every day of the year, and settles each payment individually and with finality in the participants' Federal Reserve master accounts, in central bank money. It is a credit-push service: the payer's bank sends money; nobody can pull it. The Federal Reserve raised the network's maximum transaction limit to $10 million from 12 November 2025, after an earlier increase from $500,000 to $1 million in 2025, and each institution may set lower limits of its own.

Think of FedNow as a secure courier service that runs only between banks and accepts parcels packed in one official format. A business cannot walk up to the courier itself; it has to go through its bank, which has a membership card and knows the packing rules.

A FedNow API is the friendly front desk at the bank. The business says, in a simple form, "send $2,000 to this account now", and the bank's system packs the parcel in the official format, hands it to the courier and reports back within seconds whether it was delivered or refused.

An institution can take part in FedNow in two broad ways:

• Directly. It holds a master account, connects through a FedLine solution (the Fed lists FedLine Direct, FedLine Command and FedLine Advantage for FedNow) and sends and receives ISO 20022 messages itself or through a technical service provider.
• Indirectly. It uses a correspondent bank's connection or a settlement agent's master account, which suits smaller banks and credit unions.
• Through a service provider. Many banks rely on their core banking vendor or a payments processor certified by the Fed to handle the connection and message formatting.

The messages themselves follow ISO 20022. A payment is a pacs.008 customer credit transfer; the receiving bank's acceptance or rejection comes back as a pacs.002 status report. The service also supports non-value messages such as requests for payment, requests for return of a payment sent in error, and requests for information. By 2025 more than a thousand banks and credit unions were connected.

A bank or fintech exposing FedNow to its customers usually offers endpoints along these lines:

1. Create a payment. The client posts the amount, the receiving bank's routing number, the beneficiary's account number and name, a reference and an idempotency key.
2. Funds and risk checks. The bank checks the available balance, often a cached balance, plus limits, sanctions screening and fraud rules, before anything leaves.
3. Submission and status. The bank builds the pacs.008 and sends it. The API returns a pending status, then reports "accepted" or "rejected" through a webhook once FedNow and the receiving bank respond, normally within seconds.
4. Incoming payments. Credits received over FedNow arrive as webhook events so that the business can release goods or update balances immediately.
5. Requests for payment. Where supported, the business can send a request that the payer approves in its own banking app, a pull-like experience on a push rail.

Because FedNow never closes, banks have to manage their master-account liquidity at night and over weekends; the service includes liquidity management transfers between participants for that purpose. Settlement is final and irrevocable, so a payment sent to the wrong account, or induced by a scammer, cannot be reversed by the sender's bank. The return-request message only asks the receiving bank to send the money back. This makes authorised push payment fraud a central risk, and providers rely on confirmation of the payee's name, behavioural fraud detection and per-customer limits. Irrevocability also means errors must be caught before sending, not after.

FedNow sits alongside The Clearing House's RTP network, the other US instant system, which also has a $10 million limit, and the two are not directly interoperable; banks that want full reach join both. Against an ACH API, FedNow is faster and final but has no batch or pull function, while Same Day ACH still settles only in set windows. Fedwire remains the usual route for very large, time-critical interbank transfers. Many businesses reach all of these through one bank API and choose the rail per payment, a decision often handled by a payment orchestration layer. For background on instant systems worldwide, see real-time payment systems and instant transfers.

• FedNow Service (Federal Reserve Financial Services)
• FedNow Service will raise transaction limit to $10 million (Federal Reserve Financial Services)
• FedLine Solutions (Federal Reserve Financial Services)