An ISO 20022 migration checklist for core banking teams

ISO 20022 gives payment messages structured fields for parties, purposes and remittance data. The message is only as useful as the core that stores it.

Start by listing every place the core truncates or flattens payment data. Names, addresses and references are the usual culprits.

Next, check how your ledger links an inbound message to the posting it created. Investigations and returns get much simpler when that link is explicit.

Finally, test both directions. Many banks validate outbound messages carefully and discover gaps only when a counterpart sends something unexpected.