From 31 July 2026, local USD payments are processed using either International ACH (IAT) or Real‑Time Payments (RTP). Both options allow you to send USD payments, but they work differently and may suit different operational needs.
This article explains the key differences between RTP and IAT, and helps you decide if enabling RTP is right for you.
Overview
You can choose how your local USD payments are routed:
- International ACH Transaction (IAT) - the default option
- RTP (Real‑Time Payments) - an optional, faster payment route
You are not required to adopt RTP. If you take no action, your local USD payments will be processed via International ACH (IAT).
International ACH Transaction (IAT)
What is IAT?
International ACH (IAT) is the standard ACH format used for USD payments that involve an international element.
Key characteristics
- Delivery time: Next business day (T+1)
- Cut‑off times: Unchanged
- Availability: Business days only
- Payment size limit: Up to USD 1,000,000
- Recalls and traces: Not supported
- Ultimate payer name: Not guaranteed to be displayed (depends on the receiving bank)
-
Payer address information: The following fields are mandatory where they exist in the payer’s country:
- Payer State or Province
- Payer Postcode.
More information is provided below.
What action is required for IAT?
The action you need to take as we move from ACH to IAT depends on how you currently create payments and populate payer details.
No action is required if you:
- Do not pass payer details when creating payments, and
- Do not use On-Behalf-Of (OBO) in your payment request
If you pass payer details explicitly in the payment request
- You must continue to pass the full payer object, including the complete payer address required for IAT (including state/province and postcode where applicable).
- Partial updates are not supported. If you pass payer details in the request, all required fields must be included.
If you use On‑Behalf‑Of (OBO) payments:
- Payer details are taken from the account you are making the payment on behalf of.
- To continue using On-Behalf-Of, you must ensure the account details are fully populated with the complete payer address required for IAT (including state/province and postcode where applicable).
- If these details are missing, you will need to update the account details before enforcement to avoid payment issues.
Important:
It is not possible to combine On-Behalf-Of with partial payer details.
You must either:
- rely on fully populated account details (OBO), or
- pass the full payer details in the payment request.
Real-Time Payments (RTP)
What is RTP?
RTP (Real‑Time Payments) is a US payment option that allows eligible USD payments to be processed in minutes, rather than days.
Key characteristics:
- Delivery time: Same day (T+0), typically within minutes
- Availability: 24 hours a day, 5 days a week
- Friday Cut-off time: 23:45 UK time
- Payment size limit: Up to USD 1,000,000
- Recalls and traces: Not supported
- Bank coverage: Around 77% of US banks currently support RTP (coverage continues to grow)
- Reliability: We perform an upfront check each time a payment is initiated to confirm whether the beneficiary bank is able to receive RTP. If the beneficiary bank supports RTP, the payment will be sent via RTP. If it does not, the payment will automatically be routed via International ACH (IAT), helping to avoid payment issues.
-
Payer address information: The following fields are mandatory where they exist in the payer’s country:
- Payer state or province
- Payer postcode
More information is provided below.
Enabling RTP
If you would like to enable RTP, please get in touch via your usual contact route. We will support you with completing the required contract addendum and enabling RTP.
Comparing RTP and IAT
| Real-time Payments (RTP) | International ACH (IAT) | |
|---|---|---|
| Delivery time | T+0 (minutes) | T+1 (next business day) |
| Availability |
24 hours a day, Monday - Friday Friday cut-off time: 23:45 UK time |
Business days Current cut-off times apply |
| Bank coverage | Not all US banks | All US ACH-reachable banks |
| Payer address required? | Yes | Yes |
| Recalls / traces | No | No |
| Optional? | Yes | Default |
Payer address requirements for USD payments
The same payer address requirements apply to both International ACH (IAT) and RTP payments.
Where the following address components exist in the payer’s country, they must be provided:
- Payer state or province
- Payer postcode
If a country does not use states/provinces or postcodes, these fields can be left empty, any placeholder values may lead to processing issues.
The following countries require state or province as part of a valid postal address. The payer state or province field must be populated for these countries:
- Australia
- Brazil
- Canada
- China
- India
- Malaysia
- Mexico
- US
The countries below do not use a postcode or zip code as part of the standard address system. The payer postcode field is optional for these countries and may be left blank.
- Antigua and Barbuda
- Angola
- Antarctica
- Aruba
- Bouvet Island
- Benin
- Bolivia
- Bahamas
- Botswana
- Belize
- Central African Republic
- Chad
- Comoros
- Congo (Republic of the Congo / Congo Brazzaville)
- Côte d’Ivoire
- Cook Islands
- Cameroon
- Curaçao
- Djibouti
- Dominica
- Equatorial Guinea
- Eritrea
- Fiji
- Gabon
- Grenada
- Gambia
- Guinea
- Guinea Bissau
- Guyana
- Hong Kong
- Jamaica
- Macau
- Mauritania
- Qatar
- Rwanda
- Solomon Islands
- Seychelles
- Sudan
- Sierra Leone
- Somalia
- Suriname
- São Tomé and Príncipe
- Sint Maarten
- French Southern Territories
- Togo
- Tokelau
- Timor Leste
- Tonga
- Tuvalu
- United Arab Emirates