New message format requirement for international tax payments to the U.S. Treasury

We would like to inform international taxpayers and especially Qualified Intermediaries with primary withholding responsibility (“Primary QIs”), Qualified Derivatives Dealer (“QDDs”), Withholding Foreign Partnerships (“WFPs”) and Withholding Foreign Trusts (“WFPs”) about the new message format requirement for remitting tax payments to the U.S. Treasury.

Since July 14, 2025, the U.S. Treasury rejects tax payments that do not comply with the new ISO 20022 format. QIs, QDDs and WFPs that regularly remit tax payments to the IRS have in the past generally used MT103 swift messages for this purpose. As the MT standard will be discontinued on November 22, 2025, the IRS has updated the Electronic Federal Tax Payment System Financial Institution Handbook (see page 19) showing the new format requirements for sending international tax payments as ISO 20022 pacs.008 messages.

Financial Institutions with an Electronic Federal Tax Payment System (“EFTPS”) account or a direct account with a U.S. correspondent bank for U.S. tax remittance purposes are not expected to be affected by this change, as they can rely on the EFTPS ACH debit or online banking of the U.S. correspondent bank (ACH Credit) to format the payment messages correctly.