New Amount Certainty Field in ASA

Overview

Beginning Thursday, November 5th, Authorization Stream Access requests for Mastercard transactions will include an amount_certainty field. The field indicates whether the authorized amount is expected to change at clearing. Card programs can use it to tell estimated authorizations, such as fuel or lodging pre-authorizations, apart from authorizations where the amount is final.

Details

The amount_certainty field appears at the top level of every ASA request. It is a nullable string. The key is always present, and its value is null when no certainty value applies.

Available Values

• FINAL - The network or message type commits to the amount. The authorization can still be reversed in full or in part.
• ESTIMATED - The amount is expected to change at clearing.
• UNKNOWN - The network message does not indicate whether the amount will change at clearing.
• null - No certainty value applies, or the card network does not populate the field yet.

A null value and UNKNOWN have different meanings. UNKNOWN means the network sent a message that does not indicate amount certainty. null means no certainty value applies to the message.

Each ASA request carries the value for its own network message, including incremental authorizations. A partial approval does not change the value.

Network Support

At launch, Lithic populates amount_certainty for Mastercard transactions only. ASA requests for other card networks will contain "amount_certainty": null until support for those networks ships.

Release Timeline

• Mastercard: November 5, 2026
• Other card networks and the Transactions API: November 30, 2026

User Impact

This change is additive only. Existing integrations will continue to function without modification.

Updated Documentation

For ASA request details, visit our Auth Stream Access (ASA) guide.

If you have any questions or concerns, please contact us via the HELP link in your Lithic Dashboard.

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