- Three Rails, Three Different Jobs
- What Each Rail Actually Does
A working comparison of the three U.S. payment rails businesses actually use: FedNow, RTP, and ACH. Real participant counts, current per-transaction costs, and a decision rule for when each one fits.
Quick Answer ACH moves the most dollars (USD 86.2 trillion in 2024 across 33.6 billion payments) but settles in 1-2 business days at a per-transaction cost typically under USD 1.50. RTP and FedNow both settle in seconds, both raised their transaction limit to USD 10 million in 2025, and both run 24/7/365. RTP reached the USD 10M limit first (February 2025); FedNow followed in November 2025. ACH wins on cost and reach for routine payroll and recurring billing. RTP wins on B2B vendor-pay where speed matters. FedNow wins where a smaller bank already participates in the Fed's service.
Key Takeaways
- The ACH Network processed 33.6 billion payments worth USD 86.2 trillion in 2024, with Same Day ACH passing 1.2 billion transactions for the first time.
- The RTP network handled 343 million transactions worth USD 246 billion in 2024, up 38% in volume and 94% in value, with payment value reaching USD 1.3 trillion in 2025 after the limit raise.
- The FedNow Service raised its per-transaction limit from USD 1 million to USD 10 million effective November 2025 to support corporate treasury, payroll funding, and real estate closings.
- FedNow ended 2024 with about 1,100 participating banks and credit unions; the network surpassed 1,600 participating financial institutions by late 2025.
- Same Day ACH is capped at USD 1 million per transaction until Nacha's proposed increase to USD 10 million takes effect on 19 March 2027.
Three Rails, Three Different Jobs
For business payments in the United States in 2026, you choose between three real-time and batch rails. Each one was built at a different time, by a different operator, for a different problem.
| Rail | Operator | Year Launched | Settlement Speed | 2024 Annual Volume |
|---|---|---|---|---|
| ACH | Nacha rules / Federal Reserve & EPN operators | 1974 | 1-2 business days; same-day available | 33.6 billion transactions, USD 86.2 trillion |
| RTP | The Clearing House | 2017 | Real-time; 24/7/365 | 343 million transactions, USD 246 billion |
| FedNow Service | Federal Reserve | 2023 | Real-time; 24/7/365 | About 1 million transactions, USD 38.2 billion |
Sources: Nacha 2024 ACH Network statistics, TCH RTP 2024 records, Federal Reserve Financial Services FedNow data.
ACH is the legacy workhorse: cheap, batched, slow on the calendar but enormous in scale. RTP and FedNow are the two real-time rails. They do roughly the same thing technically but with different operators, different membership networks, and different pricing structures.
What Each Rail Actually Does
ACH (Automated Clearing House)
ACH is a batch-based network that processes credit and debit transfers between U.S. financial institutions under Nacha rules. It runs on banking days, typically settling next-business-day for standard transactions and same-day for Same Day ACH (with cut-offs). ACH supports both credit pushes (you send money to someone) and debit pulls (a biller pulls from your account with authorization). The debit pull capability is unique to ACH on this list and is the main reason recurring billing and direct deposit still run on it.
Standard ACH transactions cost most businesses USD 0.20 to USD 1.50 per transaction. Same Day ACH adds a per-entry fee, typically pushing the total under USD 1.50 to USD 5 per transaction. Bank-specific daily caps usually fall between USD 2,000 and USD 25,000 per outgoing transfer, much lower than the network limit.
Same Day ACH is currently capped at USD 1 million per transaction. Nacha has proposed raising that limit to USD 10 million effective 19 March 2027.
RTP Network
RTP, operated by The Clearing House, launched in 2017 and was the first new U.S. payment rail in 40 years. It settles in seconds, 24/7/365, and supports credit-push payments only (no pull). Both sender and receiver banks must be on the RTP network for a payment to clear.
In 2024, the network handled 343 million transactions valued at USD 246 billion, with payment value up 94% year over year. Volume growth in 2024 was 38%. The network averaged more than 1 million payments per day by year-end, with 42% of transactions occurring overnight, on weekends, or on holidays.
On 9 February 2025, RTP raised its per-transaction limit from USD 1 million to USD 10 million. The change accelerated B2B adoption. By 2025, RTP processed more than USD 1.3 trillion in payment value, up about 428% from 2024.
RTP also supports Request for Payment (RfP), a structured "I am sending you an e-invoice, click to approve" flow. RfP is the operational reason RTP is gaining traction in B2B billing, not just B2C transfers.
FedNow Service
The FedNow Service is the Federal Reserve's instant payment network. It launched in July 2023, operates 24/7/365, settles in seconds, and supports credit pushes plus a Request for Payment message. Both sender and receiver banks must be FedNow participants for a payment to settle.
FedNow grew from about 400 participating financial institutions in January 2024 to about 1,100 by year-end 2024, then more than 1,600 by late 2025. In 2024, FedNow's total dollar value was about USD 38.2 billion with an average payment size of USD 25,376. In 2025, dollar value reached more than USD 853.4 billion, average payment size jumped to USD 101,435, and FedNow processed more than 8.4 million total settled payments by early 2025 metrics.
FedNow's per-transaction limit moved from USD 100,000 (launch) to USD 500,000 (mid-2024) to USD 1,000,000 (early 2025) to USD 10,000,000 effective November 2025.
Side-by-Side Comparison
| Dimension | ACH | RTP Network | FedNow Service |
|---|---|---|---|
| Operator | Nacha rules; Federal Reserve and EPN as operators | The Clearing House | Federal Reserve |
| Launch year | 1974 | 2017 | 2023 |
| Settlement speed | 1-2 business days standard; Same Day ACH same banking day | Real-time, seconds | Real-time, seconds |
| Operating hours | Banking days, cut-off times apply | 24/7/365 | 24/7/365 |
| Direction | Credit push and debit pull | Credit push only | Credit push only |
| Per-transaction limit (May 2026) | USD 1M (Same Day ACH; USD 10M proposed Mar 2027) | USD 10 million | USD 10 million |
| Typical per-transaction cost (sender) | USD 0.20 - USD 1.50 standard; up to USD 5 same-day | USD 0.25 - USD 1.00 (varies by FI) | USD 0.045 - USD 0.50 (Fed price; FI may add) |
| Reversibility | Returns allowed under Nacha rules (R-codes) | Irrevocable once cleared | Irrevocable once cleared |
| Reach (sender + receiver) | Nearly all U.S. banks | About 950 participating FIs (Q2 2025) | About 1,600 participating FIs (late 2025) |
| Request for Payment | Limited (Nacha's RFP) | Yes, native | Yes, native |
| 2024 volume | 33.6B transactions, USD 86.2T | 343M transactions, USD 246B | About 1M transactions, USD 38.2B |
Sources: Federal Reserve FedNow pricing, Nacha ACH statistics, TCH RTP 2024 records, Jack Henry FedNow vs RTP comparison.
Which Rail Fits Which Job
B2B Vendor Payment
Use RTP for high-value, urgency-driven supplier pay. Two reasons. First, RTP has been live since 2017 and has the deeper B2B adoption: about 285,000 businesses use it monthly for supply chain, bill pay, and merchant settlement. Second, RTP's Request for Payment is in active production with billers.
Use ACH for routine recurring vendor pay. If you pay a supplier monthly on standard 30-day terms with no urgency, ACH costs a fraction of RTP and runs unattended.
Use FedNow when your bank is on FedNow but not RTP. Smaller community banks and credit unions are more likely to be FedNow participants than RTP participants. If you bank with one, FedNow is your real-time option.
Payroll
Use ACH Direct Deposit for standard payroll. This is what the rail was designed for. Cost is minimal, the receive side is universal, and the timing aligns with weekly or biweekly pay calendars.
Use FedNow or RTP for instant payroll, contractor pay, or termination pay. The Federal Reserve's instant payments B2B white paper calls out payroll funding as a primary FedNow use case after the USD 10M limit raise. Late payroll, off-cycle pay, or last-day-of-employment pay are typical scenarios where real-time wins.
Refunds and Customer Disbursements
Use RTP or FedNow. Customers expect refunds fast. Insurance claim disbursements, deposit returns, and merchant refunds are high-impact use cases for both real-time rails. The marginal cost difference vs. ACH is small relative to the customer-experience gain.
Recurring Billing (Subscription, Utility, Auto-Pay)
Use ACH debit pull. Neither RTP nor FedNow supports debit pull. Billers that need to take a payment from a customer's account on a schedule still rely on ACH or card networks. RTP's Request for Payment can replace the pull model with an opt-in push, but it requires the customer to approve each transaction.
Peer-to-Peer (P2P)
Use Zelle, FedNow, or RTP. Zelle is the dominant P2P brand and runs on top of RTP and FedNow underneath the user experience. Zelle and the underlying real-time rails are economically similar; the user just sees Zelle in their bank app.
Real Estate, Treasury, Corporate Money Movement
Use RTP or FedNow now that limits are USD 10M. This is the most material change of 2025. Before November 2025, the USD 1M cap on FedNow forced most six- and seven-figure transfers to Fedwire (which has a higher cost and shorter operating window). After the USD 10M raise, escrow funding, corporate treasury sweeps, and commercial real estate closings can run on FedNow or RTP at instant speed.
Original Research: Cost-Per-Million-Dollars-Moved
To compare rails on a more useful unit than per-transaction cost, we modeled the cost of moving USD 1 million across each rail using published per-transaction prices and current limits.
| Rail | Transactions Needed | Sender Cost per Txn | Total Sender Cost | Settlement Time |
|---|---|---|---|---|
| Standard ACH | 1 transaction (next-day) | USD 0.50 (typical mid-range) | USD 0.50 | 1-2 business days |
| Same Day ACH | 1 transaction (up to USD 1M cap) | USD 1.50 - USD 5.00 | USD 1.50 - USD 5.00 | Same banking day |
| RTP | 1 transaction (limit USD 10M) | USD 0.50 - USD 1.00 | USD 0.50 - USD 1.00 | Seconds |
| FedNow | 1 transaction (limit USD 10M) | USD 0.045 (Fed) + FI markup | USD 0.10 - USD 1.00 | Seconds |
| Fedwire | 1 transaction | USD 15 - USD 50 typical | USD 15 - USD 50 | Same day, real-time |
The takeaway: per-dollar cost is now in the same order of magnitude across ACH, RTP, and FedNow. The real cost difference is operational. ACH delays cash by 1-2 days. RTP and FedNow give immediate availability. For a treasury team running daily sweeps across multiple banks, the value of one day of float on USD 10M at 5% money-market rates is roughly USD 1,370. That is the implicit subsidy ACH receives in low-rate environments and the reason corporate treasury has migrated faster than retail.
Common Misconceptions
"FedNow is replacing ACH." It is not. FedNow and RTP add a new layer for time-sensitive, irrevocable, real-time payments. ACH continues to handle recurring debit pulls, payroll, and the high-volume batch traffic neither real-time rail was built for. The Federal Reserve has explicitly stated FedNow complements rather than replaces ACH and Fedwire.
"RTP and FedNow are the same." They are functionally similar (both ISO 20022, both 24/7/365, both credit-push, both USD 10M limit) but operationally distinct. They are separate networks with separate participants. A bank on RTP only is not reachable from a FedNow-only bank, and vice versa. Large banks usually participate in both; many community banks pick one.
"All ACH is slow." Same Day ACH settled USD 3.2 trillion across 1.2 billion transactions in 2024, growing 45% year over year. For Same Day ACH, your money moves the same banking day if you make the cut-off.
"RTP is more expensive than ACH." Per transaction, RTP costs are within USD 0.50 - USD 1.00 at most participating banks. Standard ACH is cheaper per transaction (USD 0.20 - USD 1.50), but the gap narrows quickly when you factor in the operational cost of holding funds for an extra business day.
"Zelle is the same as RTP." Zelle is a consumer brand that increasingly runs over RTP and FedNow underneath but is not itself a payment rail. The transaction limits, dispute rules, and bank participation for Zelle differ from raw RTP or FedNow access.
When This Guide Isn't For You
If you are paying or receiving payments outside the United States, none of these three rails apply. SEPA Instant in Europe, FPS in the UK, NPP in Australia, and UPI in India are the international equivalents. Cross-border payments still mostly use SWIFT plus correspondent banking, though that is shifting.
If your bank is not yet a participant in RTP or FedNow, your only real-time option is wire transfer. About 1,600 financial institutions are on FedNow as of late 2025, but the United States has roughly 4,500 banks and 4,500 credit unions, so coverage is uneven, particularly among very small institutions. Check the FedNow participants directory before assuming you can send instantly.
If you are a sole proprietor running fewer than 10 payments a month, the operational lift of integrating multiple rails outweighs the savings. ACH plus card acceptance is usually enough.
How We Verified This
ACH statistics come directly from Nacha's 2024 year-end network release. RTP statistics come from The Clearing House 2024 records announcement and the ABA Banking Journal summary. FedNow participation and volume data come from the Federal Reserve Financial Services FedNow Volume and Value page, the September 2025 press release on the USD 10M limit, and the ABA Banking Journal FedNow developments roundup. Per-transaction costs were cross-referenced between vendor pricing pages, Nacha's published guides, and recent Payments Dive coverage.
Frequently Asked Questions
Are FedNow and RTP the same?
No. They are two separate real-time payment networks with separate operators, participant lists, and pricing. FedNow is operated by the Federal Reserve. RTP is operated by The Clearing House. Both settle in seconds, both run 24/7/365, both use ISO 20022 messaging, and both raised their per-transaction limit to USD 10 million in 2025. A payment sent from a FedNow-only bank cannot settle to an RTP-only bank without an interbank bridge or alternative rail.
Is FedNow replacing ACH?
No. FedNow is an instant credit-push rail. ACH supports both credit push and debit pull and remains the primary U.S. rail for payroll direct deposit, recurring billing, and high-volume B2B settlement. The Federal Reserve's own communications describe FedNow as complementary to ACH and Fedwire rather than a replacement.
Are RTP payments ACH payments?
No. RTP and ACH are separate networks operated by different entities under different rule sets. RTP transactions are irrevocable; ACH transactions can be returned under Nacha R-codes within defined windows. RTP settles in seconds; ACH settles in 1-2 business days, or same banking day for Same Day ACH.
Is FedNow an ACH?
No. FedNow is the Federal Reserve's instant payment service, distinct from FedACH. FedACH is the Federal Reserve's role as one operator of the ACH network alongside The Clearing House's Electronic Payments Network (EPN). FedNow runs on different infrastructure, with different messaging (ISO 20022), different operating hours (24/7), and different settlement (real-time).
Why would I use FedNow instead of RTP?
The most common reason is that your bank participates in FedNow but not RTP. As of late 2025, FedNow has about 1,600 participating financial institutions; RTP has about 950 in active production for B2B traffic. Smaller community banks and credit unions are more likely to be FedNow-only because the Federal Reserve does not require minimum volume or asset commitments to join.