Scheme code system · UnionPay
Official, limited scopeA0
Message authentication code verification failed
The request failed a security, cryptographic, or source-validation condition.
- Outcome
- Declined
- Code system
- UnionPay
- Raw format
- Two-character alphanumeric DE 39 response code
Operational context
No universal retry instruction encoded
UnionPay wording mapped to the SchemeLens “Security violation” concept.
Use the current scheme, provider, transaction, and advice-code rules; the raw response value alone may be insufficient for a retry decision.
Explicit mapping
SchemeLens concepts
These links are editorial mappings, not replacements for the raw source value. The relation shows how closely the wording aligns.
| Concept | Relation | Mapping note |
|---|---|---|
| Security violation | Narrower than concept | UnionPay wording mapped to the SchemeLens “Security violation” concept. |
Provenance
Sources used for this record
- China UnionPay Open Platform: Industry and Content System Interface Specification — Appendix BOfficial, limited-scope source for two-character DE 39 values used by the documented CUPS industry and content interface.Online specification, updated 24 August 2020; verified 27 July 2026
SchemeLens keeps source wording, normalized concepts, and operational guidance separate so later evidence can be added without rewriting the raw record.