AMEX to MT940 converter
American Express has no IBAN and reports spend as a positive number — two reasons an AMEX export will not import as-is. Both are handled during conversion.
Upload your AMEX statement →2 free conversions · no credit card required
AMEX to MT940 in 3 steps
- Export the AMEX statement. Download the card statement as CSV from the American Express portal, one card at a time.
- Negate the amounts. AMEX shows spend as positive. In MT940 an expense has to be negative (debit), so tick 'negate amounts' to flip the sign.
- Download the MT940 file. A valid fictitious IBAN is generated per card so your package accepts the file and maps it to the AMEX ledger.
Booking AMEX correctly
No IBAN, so a generated one
AMEX works with card numbers. The generated account number passes the mod-97 check accounting packages apply.
The direct debit is a transfer
The monthly AMEX collection on your bank account is not a cost — it is an internal transfer between the AMEX ledger and the bank ledger.
One ledger per card
Keep business and personal cards apart, each with its own ledger and account number, or the split is lost.
Spend arrives positive
Every AMEX export does this. Forgetting to negate puts every expense on the wrong side of the ledger.
Frequently asked questions
Does AMEX have an IBAN I can use in my accounting?
No. American Express works with card numbers and has no IBAN. Use a fictitious IBAN per card; it is written into the MT940 so your package accepts the file and maps it to the right ledger.
Why do I need to tick 'negate amounts' for AMEX?
AMEX exports show spend as a positive number. In MT940 an expense has to be negative (debit). Negating flips the sign so your books read the transactions the right way round.
What do I book against the AMEX direct debit on my bank account?
The monthly AMEX collection on your business account is not a cost — it is an internal transfer between the AMEX ledger and the bank ledger. The individual expenses are booked on the AMEX ledger.
Can I mix business and personal AMEX cards?
Process them separately, with their own ledger and fictitious IBAN per card. Mixing them loses the split between business and personal spend.
My accounting package rejects the fictitious IBAN. Now what?
Some packages validate the IBAN mod-97 check. Use the 'generate fictitious IBAN' function in the app rather than inventing a number yourself — the generated one passes that check.