Notes from getting QuickBooks to accept a generated .qbo file

I'm building a small tool that converts bank CSV files into .qbo files for QuickBooks (qbofile.com). When a generated file is wrong, QuickBooks rejects it with vague errors and the OFX spec doesn't tell you what QuickBooks actually checks. So I ran some experiments. Notes below, in case someone else hits the same wall.

The file is not XML

.qbo is Intuit's version of OFX 1.0.2, which is SGML. Leaf tags have no closing tag:

<TRNAMT>-42.50
<FITID>8f3a2b...

Only aggregate tags close. The file also needs a 9-line key:value header, then one blank line, then the body. Line endings are CRLF. My first bug was closing every tag like XML.

"Missing bid data" means one tag: INTU.BID

QuickBooks checks <INTU.BID> against an internal list of banks that pay Intuit for Web Connect. I tested three variants on QuickBooks Desktop for Mac 2024:

So the whole <FI> block (bank name, org id) can be dropped, but INTU.BID cannot. I have only tested the Mac version. If you know whether Windows versions behave the same, I'd like to hear.

FITID decides duplicates

QuickBooks dedupes on FITID, not on date + amount. If a converter generates random FITIDs, re-importing an overlapping date range creates duplicate transactions. I hash account + date + amount + description, so the same transaction always gets the same FITID. Credit card statement cycles never match calendar months, so overlapping imports happen more often than I expected.

QuickBooks cannot export .qbo

This one surprised me. No version of QuickBooks can produce a .qbo file. The format only goes one direction, from bank to QuickBooks. Every .qbo file in the world came from a bank's download button or from a converter.

That's what I have so far. The tool is free for single files and runs fully in the browser, nothing gets uploaded. I have only tested against QuickBooks Desktop — if you use QuickBooks Online, I'm interested in what its importer accepts.