Scheme code system · Mastercard
Official, limited scope94
Duplicate transmission detected
The request matches a transaction already seen by the receiving system.
- Outcome
- Technical
- Code system
- Mastercard
- Raw format
- Two-character DE 39 response code
Operational context
Evaluate the advice code
For merchant-initiated transactions, evaluate DE 39 together with DE 48.84 Merchant Advice Code. MAC 02 means wait 24 hours; MAC 03 or 21 means do not retry.
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 |
|---|---|---|
| Duplicate transmission | Direct semantic match | Mastercard wording mapped to the SchemeLens “Duplicate transmission” concept. |
Namespace check
The same raw value exists elsewhere
- Visa 94Request is identified as a duplicate
- Discover 94Duplicate transmission detected
- UnionPay 94Duplicate transaction
- EBANX 94Transmission duplicates an earlier request
Provenance
Sources used for this record
- Mastercard: Transaction Processing RulesOfficial source for published DE 39 values and selected Merchant Advice Code rules; not a complete public technical specification.9 December 2025
SchemeLens keeps source wording, normalized concepts, and operational guidance separate so later evidence can be added without rewriting the raw record.