Deep dive: instant payments for B2B

Instant payments for B2B: what's real

My view as of October 2026: for business payments, the useful part of an instant rail is that the money is final and can carry the invoice with it. Speed matters for a minority of payments. The evidence is weakest on usage: no one publishes the business share of RTP or FedNow, or how many requests for payment get paid.

Does a business payment need to settle in seconds?

Mostly no. A supplier on 30-day terms gains little from money that lands at 2 a.m. instead of the next morning: at a 3.5% annual cost of money, getting $50,000 a day sooner is worth about $4.79.

The volume says the same. Same Day ACH, a batch rail that settles in three windows a day, moved about $3.9 trillion in 2025, more than RTP and FedNow together (roughly $2.2 trillion, by my arithmetic). Nacha is raising its per-payment cap from $1 million to $10 million on September 17, 2027, so the incumbent is reaching for high-value business payments too.

Nobody measures the business share of US instant payments. The only proxy is the average payment: about $4,100 on RTP in Q3 2026 and about $55,000 on FedNow in Q2. Those aren't consumer sizes, and the Richmond Fed names uses where timing does matter: property settlements, payroll and moving money out of brokerage accounts. The last public hint on direction is from mid-2024, when businesses sent about 80% of RTP payments but 95% of those went to consumers, which points to payouts more than supplier invoices.

Certainty and data over speed

A receivables team wants a payment it can count as final and match without a person, and instant rails give both. Settlement is final in law, so no ACH-style return arrives two days later. A request for payment carries the invoice reference, the payment returns it as its end-to-end ID, and FedNow accepts far more structured remittance than ACH's 80 characters.

That certainty needs a name check to be real, because a final payment to the wrong account is final too. Pix shows the data side working: dynamic QR codes, each carrying one charge's details, started about 40% of Pix payments in 2025.

Same Day ACH or RTP and FedNow

For a US product I'd treat them as partners: Same Day ACH reaches every payer's bank on banking days, and RTP and FedNow cover nights, weekends and payments where finality matters.

Request for payment: the data doesn't exist

Both US networks support requests for payment, at a cent each. The Richmond Fed says there are no usage figures, and I found none anywhere: not how many are sent, how many get paid or how many carry structured remittance. The design is sound; what could stop it is the payer's bank never showing the request.

Other countries got further by changing what "request" means. Brazil's dynamic QR code works like a request the payer scans. Pix Automático, live since June 2025, lets a business pull recurring payments after one authorization, though by December 2025 it carried only about R$133 million a month for just over 1,000 businesses. India went the other way: NPCI ended person-to-person collect requests on October 1, 2025 because scammers abused them, and kept merchant requests.

Pay by bank or card

For a seller, a card on a $50,000 invoice costs hundreds of times what a bank payment does. The card survives because it pays the buyer: float until the card bill is due, rewards and chargeback rights. In the AFP's 2022 survey, businesses were "more eager to accept cards than issue them".

Pay by bank has to fill those gaps. In the UK, Visa A2A and Mastercard's A2A Protect sell protection on top of bank payments, and one payments consultancy says discounts and cashback move shoppers. In the US, the Kansas City Fed found in July 2026 that pay by bank "has yet to become available at points of sale". For invoices I'd offer pay by bank as the cheap option next to the card and let the price difference work.

A $50,000 invoice, rail by rail

Bank prices are one US bank's published small-business schedule (May 2026); card costs are Visa's published US interchange (April 2026) and Stripe's list price; the rest are network fees.

The card range runs from Visa's lowest published business rate at this size (0.95% plus $35) to Stripe's 2.9% plus 30 cents. RTP or FedNow costs the two companies about $2.40 together, 0.005% of the invoice. Beside the card, the choice between ACH, instant and a wire is small change; between those three, what differs is when the money arrives, whether it can come back and whether the invoice number survives the trip.