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SchemeLens

ISO 8583:1993 response code

921

Security software/hardware error - no action

Standard version
ISO 8583:1993
Paired version code
No direct pair assigned

In ISO 8583:1993, response code 921 means “Security software/hardware error - no action”. No reviewed scheme source contains a corresponding entry on this row, so all five scheme columns are shown as N/A.

Merchant handling

Actions to be taken

Do not assume approval. Check the existing transaction status before correcting the request or retrying, so a late response does not create a duplicate authorization.

This is conservative merchant guidance derived from the published response meaning. Current scheme, acquirer, processor, merchant advice, and transaction-specific rules take precedence.

Scheme comparison

Descriptions in the reviewed sources

Each populated value links to its scheme record and preserves the raw code published by that source. N/A means no matching description exists in the reviewed public dataset.

Scheme descriptions compared with ISO 8583:1993 response code 921
SchemeRaw codeSource descriptionEvidence
VisaN/AN/AN/A
MastercardN/AN/AN/A
American ExpressN/AN/AN/A
DiscoverN/AN/AN/A
UnionPayN/AN/AN/A

Standard sources

Version and response-name evidence