August 2026

Aug 17, 2026

Citibank China Payment Rules

We published payment rules for Citibank China via Acme batch payments. The page covers field validation and constraints for CN_ACH, CN_RTGS, CN_TT_INTL, and CN_TT_DOM, including SAFE BOP regulatory reporting for the TT types.

Link to payment rules:

• Acme Citibank China Payments

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Aug 14, 2026

Direct Debit Authorization payerAuthorizedMaxAmount (API)

Direct Debit Authorization API responses and webhooks now include payerAuthorizedMaxAmount: the maximum payment amount the payer authorized with their bank, in SGD minor units.

• Only a non-zero value for Singapore eGIRO Direct Debit Authorizations, and only after the payer has approved.
• Returns 0 before approval (including on Create), when the bank did not return a payer-set limit, and for other DDA types (for example HK or Malaysia FPX). Use precheckMaxAmount for the Acme-side cap on those types.

Affected pages:

• List Direct Debit Authorizations
• Get a Direct Debit Authorization
• Acme webhook examples

Mock payerIdType and payerIdHash in Direct Debit Authorization test mode (API)

Successful Singapore eGIRO Direct Debit Authorizations in test mode now return mock payer identification fields, so you can test hash handling without a live bank.

• payerIdType is NRIC.
• payerIdHash is the SHA-256 hex digest of uppercased S1234567D.
• Live mode, Malaysia, and Hong Kong are unchanged.

Affected pages:

• Special Test Mode Values

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Aug 7, 2026

Documentation: Maybank Singapore, Citibank Taiwan, and Banco Azteca Mexico Payment Rules Corrected

We corrected the payment rules pages below to match Acme's validation. The validation behavior is unchanged.

Maybank Singapore (H2H):

• paymentDetails and purposeCode must not be provided for BKTR payments. They were previously documented as optional, and the BKTR example request was corrected accordingly.
• purposeCode allows up to 5 characters. It was previously stated as 35.
• receiver.bankAccountNumber accepts digits only. It was previously stated as alphanumeric.
• FAST and PAYNOW payments must not be more than SGD 200,000 in amount. This limit was previously undocumented.
• BKTR payments are not restricted to SGD. Currency was previously documented as SGD only for all payment types.
• receiver.bank is validated as alphanumeric with a maximum of 11 characters, not against the BIC pattern.

Citibank Taiwan (H2H):

• The full receiver address must fit in 3 lines of 35 SWIFT characters. It was previously stated as 2 lines.

Banco Azteca Mexico (API):

• Field names in the tables were corrected to the single payment request format (for example customerReference instead of payments[N].customerReference).

Affected pages:

• Acme Maybank Singapore Payments (H2H)
• Acme Citibank Taiwan Payments (H2H)
• Acme Banco Azteca Mexico Payments (API)

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Aug 6, 2026

Maybank Singapore Payment Status Mapping

We documented how Maybank Singapore (H2H) transaction statuses map to Acme payment statuses on the payment rules page.

Link to payment rules:

• Acme Maybank Singapore Payments (H2H)

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Aug 4, 2026

Per-payment Currency in Batch Payments (API)

The Create a Batch Payment API now accepts an optional currency field on each individual payment.

• When omitted, the payment uses the batch-level currency.
• When provided, it overrides the batch-level currency for that payment.
• The currency must be a currency supported by the payment type.

Affected pages:

• Create a Batch Payment
• Batch Payments