Last reviewed: · Curated by Ohmyfin Organisation editorial.
Field 21 on an MT103 is the Related Reference — used to point at another SWIFT message that this payment relates to. Optional in plain MT103, mandatory in some MT103 STP variants.
How an MT103 maps to the UETR (field 121), sender reference (field 20), value-date/currency/amount (field 32A) and beneficiary details. Source: SWIFT MT103 specification.
Details
Format: up to 16 characters. When present, it usually echoes the field 20 of the message being referenced (an earlier MT103 being amended, an inquiry, a return).
Quick facts
SWIFT field specification
Example value
:21:RELATED-REF-PRIOR
Valid characters / format
16x alphanumeric
Required on MT103
Optional
Required on MT202
Mandatory
Required on pacs.008
Optional
Notes
Related reference (links cover MT202 to its underlying MT103).
Key facts
Optional in standard MT103
Format: 16x — up to 16 characters
Points back at a related earlier message
Frequently asked questions
When is field 21 used?
In returns, amendments, status inquiries, or to chain together related transactions in a treasury workflow.
Related — more from swift field reference and beyond
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