Parse an MT940 Statement into Reconciliation Data

Skill: Convert a SWIFT MT940 customer statement into structured reconciliation data

Region: Global (SWIFT FIN standard) Category: Banking — SWIFT MT940 Customer Statement Message Does: Takes a SWIFT MT940 end-of-day customer statement (the tag-based text format) and extracts a flat, postable reconciliation dataset — the :20: / :25: / :28C: / :60F: / :61: / :86: / :62F: tags, transaction-type (SWIFT) codes, and opening/closing-balance continuity checks. Schema version: SWIFT MT940 (FIN Customer Statement; Category 9)

The AI parses and structures the statement; it does not connect to your bank. MT940 :86: narrative formatting is bank-specific (German banks use structured ?20–?29 subfields; others use free text). Always reconcile the opening + entries against the closing balance before posting.

When this applies

• Daily cash application and bank reconciliation from legacy SWIFT statements.
• Banks/regions that still deliver MT940 rather than ISO 20022 camt.053.
• Feeding an ERP/treasury system that imports MT940.

Parsing procedure

1. Read the source — an MT940 text block. A file may hold several statements; split on each :20: transaction-reference tag.
2. Header tags — :20: transaction reference, :25: account identification, :28C: statement/sequence number.
3. Opening balance :60F: (or :60M: intermediate) — parse D|C mark, date YYMMDD, currency, amount (comma decimal).
4. Statement lines :61: — value date YYMMDD, optional entry date MMDD, D|C(or RD/RC reversal) mark, amount, transaction-type code (N/S/F + 3-char code), customer & bank references.
5. Information :86: — narrative tied to the preceding :61:; extract counterparty name, IBAN, and remittance (parse ?-subfields if present).
6. Closing balance :62F: (or :62M:) — same layout as :60F:.
7. Normalize — comma decimal 1500,00 → 1500.00; YYMMDD → YYYY-MM-DD; sign each amount (C positive, D negative; reversals flip).
8. Reconcile — opening + Σ signed :61: amounts must equal :62F:; flag any gap.
9. Emit — a structured JSON reconciliation dataset, per the worked example.

MT940 tag → field map

Statement-line :61: layout

:61:YYMMDD[MMDD]<mark><amount><type-code><cust-ref>//<bank-ref>
       │     │     │       │        │          │          └ account-servicing ref
       │     │     │       │        │          └ customer reference
       │     │     │       │        └ N/S/F + 3-char transaction type code
       │     │     │       └ amount (comma decimal)
       │     │     └ C | D | RC | RD (credit/debit, Rx = reversal)
       │     └ optional entry date (MMDD)
       └ value date (YYMMDD)

Code tables

Debit/Credit mark (:60F:/:61:/:62F:)

Transaction type identifier (:61:)

Common N codes: NTRF transfer, NDDT direct debit, NCHG charges, NINT interest, NRTI returned item.

Calculation rules

• Comma is the decimal separator in MT940: 1.234,56 → 1234.56.
• Signed amount: C → positive, D → negative; RC/RD flip the sign of the original.
• Reconciliation invariant: :60F: amount + Σ signed :61: amounts = :62F: amount. Mismatch ⇒ flag (often a parsing error in :86:-split lines).
• Statement continuity: the :60F: of one statement should equal the prior :62F: (same account/currency).

Worked example (end-to-end)

Input — MT940 statement

:20:STMT260611
:25:DE21500500009876543210
:28C:00115/001
:60F:C260611EUR10000,00
:61:2606110611C1500,00NTRFINV-7781//BANKREF001
:86:166?20Invoice INV-7781?32ACME SUPPLIES LTD?31DE89370400440532013000
:62F:C260611EUR11500,00

Output — reconciliation dataset (JSON)

{
  "account": { "id": "DE21500500009876543210", "currency": "EUR" },
  "statement": { "reference": "STMT260611", "number": "00115/001" },
  "balances": { "opening": 10000.00, "closing": 11500.00 },
  "entries": [
    {
      "valueDate": "2026-06-11",
      "entryDate": "2026-06-11",
      "amount": 1500.00,
      "typeCode": "NTRF",
      "customerRef": "INV-7781",
      "bankRef": "BANKREF001",
      "counterparty": "ACME SUPPLIES LTD",
      "counterpartyIban": "DE89370400440532013000",
      "remittance": "Invoice INV-7781"
    }
  ],
  "reconciliation": { "expectedClosing": 11500.00, "balances": true }
}

Normalization notes: 10000,00 → 10000.00; value date 260611 → 2026-06-11; :86: ?20→remittance, ?31→counterparty IBAN, ?32→counterparty name; reconcile 10000.00 + 1500.00 = 11500.00.

Validation checklist

• Multi-statement files split on each :20:
• :60F: opening and :62F: closing balances parsed with correct D/C sign
• Each :61: line: value date, mark, amount (comma decimal), type code, references
• :86: narrative mapped to the preceding :61: (bank-specific ?-subfields handled)
• Amounts signed; reversals (RC/RD) flip the sign
• opening + Σ entries = closing (discrepancy flagged)
• Statement continuity: this :60F: = prior :62F: for the same account

Last updated: 2026-06-12 — confirm your bank's :86: narrative convention (structured ?-subfields vs free text) and transaction-type code set before posting.