AI agents for business finance: what they can and can't do
What AI agents can do in bookkeeping, close, collections and compliance today, where a person must stay in charge, and how to judge a product.
Part of the guideOne account, every currency: a guide for cross-border businesses
The short answer
Use ACH for routine, predictable US dollar payments such as supplier runs, payroll and subscriptions: it is cheap, handles large batches, and Same Day ACH settles within the day for payments up to $1 million. Use a wire for urgent, high-value or one-off payments that must arrive the same day and be final, such as property completions or acquisitions, because Fedwire settles each payment individually and irrevocably. The trade-off is cost and reversibility: wires usually cost more and cannot be pulled back once processed.
In the US, nearly every business-to-business dollar payment travels by ACH or by wire. They are not competing products so much as tools for different jobs. This article explains how each works, with the limits and cut-off times that apply in October 2026. If you are receiving dollars from outside the US, our guide to multi-currency business accounts explains how local US account details let customers pay you either way.
The key differences
| ACH | Wire (Fedwire) | |
|---|---|---|
| How it settles | In batches, at set times | Individually, in real time |
| Speed | Next business day; Same Day ACH within the day | Same day, usually within hours of sending |
| Per-payment limit | No network limit for standard ACH; $1 million for Same Day ACH (rising to $10 million on 17 September 2027) | No network limit; banks set their own |
| Cost to the business | Usually low or free | Usually a fee per payment, higher than ACH |
| Reversibility | Entries can be returned for set reasons within time limits | Final and irrevocable once processed |
| Best for | Payroll, supplier runs, recurring bills, collections | Urgent, large or one-off payments |
How ACH works for a business
ACH is a batch network governed by rules from Nacha. Your bank collects payment instructions through the day and sends them in files; they settle at fixed times. It handles both credits (you push money to someone) and debits (you pull money from a customer who has authorised it). The scale is large: Nacha reported 35.2 billion payments worth $93 trillion in 2025, of which about 8.1 billion were business-to-business, up almost 10% on the year.
Same Day ACH is the faster option within the same network. There are three processing windows each business day, with submission deadlines for banks of 10:30 am, 2:45 pm and 4:45 pm Eastern Time; your own bank's cut-offs will be earlier. Same Day ACH carried 1.4 billion payments worth $3.9 trillion in 2025. The per-payment cap is $1 million today; Nacha announced in April 2026 that it will rise to $10 million from 17 September 2027. International ACH transactions are not eligible for same-day processing.
ACH debits deserve a separate note. If you bill customers on a regular cycle, collecting by ACH debit with their written authorisation can cut late payments, because you start the payment rather than waiting for theirs. The cost is that debits can be returned, for example if the account lacks funds or the customer disputes the authorisation, so the cash is less certain than a wire until the return window has passed.
How a wire works
A domestic wire in the US normally travels over the Fedwire Funds Service, run by the Federal Reserve Banks. Each payment is debited from the sending bank's account at the Fed and credited to the receiving bank's account, one at a time. Transfers are immediate, final and irrevocable once processed.
Fedwire's business day runs from 9 pm Eastern Time on the previous calendar day to 7 pm, Monday to Friday, excluding holidays. Transfers for bank customers must be sent by 6:45 pm, and banks set earlier internal cut-offs. Since 14 July 2025, Fedwire has used the ISO 20022 message standard, which carries more structured information about the payer and payee. An international wire in dollars is different: it travels over the Swift network and may pass through correspondent banks; see SWIFT vs local payment rails.
Worked example: three payments, three choices
A US company with a UK parent has three payments to make on the same Tuesday.
| Payment | Amount | Deadline | Best route | Why |
|---|---|---|---|---|
| Monthly contractor run: 40 people at $2,500 each | $100,000 in 40 payments | Friday | Standard ACH batch | Low cost per payment, one file, plenty of time |
| Supplier invoice due tomorrow | $250,000 | Wednesday | Same Day ACH or standard ACH sent today | Within the $1 million Same Day cap; no need to pay for a wire |
| Completion on a warehouse lease deposit | $1,500,000 | Today, before 3 pm | Wire | Above the Same Day ACH cap and must be final on the day |
On the ACH side, the network charges banks a small fee per Same Day entry, 5.2 cents, which banks may or may not pass on. Wire pricing is set by each bank and varies widely, so check your price list. For forty contractor payments, sending forty wires would multiply that per-payment fee for no benefit; for the lease deposit, the wire's finality and speed are worth the cost. Had the deposit been $900,000, Same Day ACH would have been allowed, but counterparties in property and acquisition deals often still ask for a wire because a final, same-day payment is easier for both sides to confirm.
When you are the one being paid, the choice is usually the customer's. Put both the ACH and the wire details on your invoice, clearly labelled, and let the payer use whichever suits their process. Large corporate payers often send ACH by default and wires only on request.
Errors, fraud and what can be undone
Finality cuts both ways. A wire to the wrong account, or to a fraudster who has changed an invoice's bank details, is very hard to recover. ACH entries can be returned for specific reasons within the time limits in the Nacha rules, which gives some room to correct errors, but a credit that has already been withdrawn is still hard to recover in practice.
- Confirm any new or changed bank details by phoning a number you already hold, not one in the email that announced the change.
- Require a second approver for wires and for ACH batches above a threshold.
- Send a small test payment before a large first payment to a new payee.
- Ask whether the payee wants the ACH or the wire routing number; some banks use different ones.
Our explainer on routing numbers, IBANs and SWIFT codes covers the last point in more detail.
Where Pryme fits
Pryme accounts hold NGN, USD, GBP and EUR, with local details for each currency, including a US account and routing number, and dollars stay as dollars when they arrive. Check in the app which local details and payment types your business account shows before you put them on an invoice. When you pay several people at once, bulk payouts check account names before you approve the batch, and approval thresholds with a second named approver apply to large payments.
Outside Nigeria, Pryme's services are provided through regulated partners. Whichever provider you use, ask which US payment types it can send and receive, and what each costs, before you plan a supplier run around it. For how receiving, converting and protecting money fit together, see the multi-currency business account guide.
Questions people ask
Is ACH or wire faster?
A wire is usually faster for a single payment: it settles individually on the same day. Same Day ACH has narrowed the gap, settling within the day in set windows for payments up to $1 million. Standard ACH usually settles the next business day.
Is ACH safer than a wire transfer?
Neither is safer in itself, but ACH entries can be returned for specific reasons within time limits, while a wire is final once processed. That makes mistakes and fraud with wires harder to undo. Verify bank details carefully before any large payment.
What is the Same Day ACH limit in 2026?
$1 million per payment. Nacha has approved an increase to $10 million, effective 17 September 2027. Standard next-day ACH has no network limit, though banks set their own.
What time is the wire cut-off in the US?
Fedwire accepts transfers for bank customers until 6:45 pm Eastern Time on business days, but each bank sets an earlier internal cut-off, often in the afternoon. Check your bank's cut-off, especially for time-critical payments.
Can I receive ACH payments if my business is outside the US?
Yes, if you have US account and routing details, typically through a provider that issues them via a US partner bank. Your customers then pay you by ACH or domestic wire as they would a US supplier.
Sources
- Nacha: Same Day ACH and business-to-business payments propel ACH Network volume growth in 2025 · accessed Oct 2026
- Nacha: Same Day ACH per-payment limit to increase to $10 million (Apr 2026) · accessed Oct 2026
- Open Exam Prep: Same Day ACH windows, limits and eligibility · accessed Oct 2026
- Federal Reserve: Fedwire Funds Services · accessed Oct 2026
- Federal Reserve Financial Services: Fedwire Funds Service operating hours · accessed Oct 2026
- Federal Reserve Financial Services: Fedwire ISO 20022 implementation FAQ · accessed Oct 2026
This article is general information, not financial, legal or tax advice. Products described are provided under the terms on this site and are subject to regulation and eligibility.