Open banking feeds vs. statement files: what actually changes
Intraday API feeds and overnight statement files solve different problems. A practical comparison for finance teams deciding how to connect their banks.
Every connectivity conversation we have starts in the same place: should we take an API feed or keep the overnight file? The honest answer for most groups is both, and knowing why comes down to what each is actually good at.
Statement files
The overnight statement file — CAMT.053 in the ISO 20022 family, MT940 in the older SWIFT format, BAI2 in North America — is the accounting record of a banking day. It is complete, it is reconciled by the bank, and it is what your auditors expect to see behind a closing balance.
It is also a day late. A file describing Tuesday arrives on Wednesday morning. For reconciliation and for the closing position that is exactly right. For knowing whether a large receipt has landed, it is useless.
Open banking feeds
An authorised account information feed gives you balances and transactions during the day, refreshed as often as the bank permits. That is what makes an intraday position possible, and it is what lets you answer "has it arrived yet" without opening a bank portal.
The trade-offs are real. Consent has to be renewed periodically, which needs an owner and a calendar reminder. Coverage varies by bank and by account type — notice deposits and pooled accounts are often outside scope. And intraday balances are provisional; they can and do change before the day closes.
Use both, for different jobs
The pattern that works is straightforward.
- Intraday feed for visibility. What is the balance right now, what has come in today, is anything unexpected moving.
- Overnight file for the record. What was the closing balance, what is the reconciled transaction list, what goes into the report and the audit trail.
When the two disagree, the file wins. Building that rule in from the start avoids a category of confusion later.
What to check before you commit
- Which of your banks support account information access in each country you operate in, and for which account types.
- Whether pooled, notice and escrow accounts are included or excluded.
- How consent renewal works, and who at your organisation owns it.
- Whether the file format your bank produces is the current standard or a dialect of it — MT940 in particular varies considerably between banks.
- What happens to a file that arrives late or not at all, and how you find out.
That last one matters more than it sounds. A missing file is the single most common cause of a position that is quietly wrong, and the only defence is a system that notices and tells someone.