Before converting a bank CSV: check dates, signs and the target importer

A bank CSV can look tidy and still describe the wrong transactions after an import. The useful question is whether the destination receives the same dates and amounts that you intended.

One starting check can save a conversion step: QuickBooks Online already supports CSV uploads. Intuit documents supported three-column and four-column layouts in its manual upload guide. Check the current instructions for your country and product first. You may not need another file format.

If your particular destination needs OFX, QBO or QFX, make a tiny example before moving a full statement.

Start with two transactions whose meaning you know

This is invented data for an asset-account example, not a real bank statement:

Date,Description,Amount
2026-11-01,Synthetic incoming payment,125.00
2026-11-02,Synthetic outgoing payment,-35.50

For this example, there are two transactions and a net movement of 89.50. Those are simple checks you can carry into the preview and destination. A converter producing a downloadable file does not prove the target application interpreted it correctly.

Check the date convention before exporting

03/04 cannot tell you by itself whether the date is March 4 or April 3. Use the convention documented by the source bank and inspect a transaction whose real date you know. Avoid letting a spreadsheet silently decide while you clean the file.

Check signs and column meaning

A balance column is not a transaction amount column. Separate money-in and money-out columns also need an explicit mapping. Inspect one known incoming and one known outgoing transaction in the target preview; do not apply this invented asset-account sign convention blindly to every statement type.

Check the exact import path

File extensions do not make formats interchangeable. The OFX 2.3 specification describes the move from SGML formatting to XML. Use the format and version supported by the destination; renaming a file is not a conversion.

Before a full import, review a small sample and check how the destination handles an overlapping date range. Two transactions with the same date and amount can be legitimate, so deleting apparent duplicates without checking the statement can create another error.

The tool we build, and the limit of our test

Our Luventra converter converts CSV to OFX/QBO/QFX in the browser. The current guest allowance is two files per day, up to 50 transactions per file.

In our 10 November synthetic browser check, a two-row OFX download preserved amounts of 125.00 and -35.50. That test did not include an accounting-application import, a payment, or a real customer statement. It supports a narrow claim about that export, rather than universal compatibility.

Keep the original export, inspect the preview and verify the target import before relying on a converted statement.