Sender Reference (Field 20)

Field 20 on an MT103 is the Sender's Reference — a unique identifier that the sending bank assigns to its outgoing payment. It is up to 16 characters of letters, numbers and slashes. Track a payment by sender reference free →

Details

Field 20 is mandatory on every SWIFT MT103 and is sometimes called the "TRN" (Transaction Reference Number). It is the value you cite when calling your bank's customer service to ask "where is my payment?" — the bank's internal system looks up the TRN to find the specific transaction. The format is up to 16 characters of letters (A–Z, a–z), digits (0–9) and slashes (/). The reference cannot start or end with a slash, and cannot contain two consecutive slashes, because SWIFT MT parsing uses slashes as field delimiters and double-slashes as special markers.

Field 20 must be unique within the sending bank — though different banks can independently use the same TRN value without conflict, because TRNs are bank-scoped rather than globally unique. This bank-specificity is the core limitation of the TRN compared to the UETR (field 121): if a payment passes through five banks, each bank has its own TRN in its records, while the UETR is the same at every bank along the chain. For cross-bank tracking, the UETR is far more reliable.

The sender's reference (field 20) is the value you typically see on a wire transfer receipt from your bank, labelled "payment reference", "transaction reference", "SWIFT reference" or similar. When the beneficiary bank books the incoming credit, it often shows the field 20 value on the beneficiary's bank statement as the payment reference — though the bank may substitute its own internal booking reference. This is why beneficiaries sometimes see a different reference from the one the sender used.

Corporate treasury systems often populate field 20 with a standardised internal reference format — for example "INV-2024-0001" or "PAY000123" — that matches the ERP payment run ID. This enables automated reconciliation by the bank reporting back with the same reference. However, the 16-character limit is tight for complex reference formats, and many corporates have to truncate or encode their internal reference to fit.

On Ohmyfin, you can search for a payment by its sender reference (field 20) if you do not have the UETR (field 121). Ohmyfin will attempt to locate the payment in the SWIFT GPI network by reference. If found, Ohmyfin returns the UETR and the full tracking status. If not found (e.g. the payment is too old, or the bank's reference is not indexed), you will need to obtain the UETR from the sending bank directly.

Key facts

• Mandatory MT103 field — up to 16 alphanumeric characters and slashes
• No leading/trailing slashes; no consecutive slashes
• Unique within the sending bank only — changes at each hop
• Often called the "TRN" (Transaction Reference Number) by customer service
• For end-to-end tracking across all banks, use the UETR (field 121) instead
• Ohmyfin accepts sender references as lookup inputs alongside UETRs

Frequently asked questions

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