Convert IIF to CSV for QuickBooks Review and Cleanup

IIF Is Not a Bank CSV

IIF (Intuit Interchange Format) is a text format QuickBooks Desktop uses to import and export lists and transactions. It looks a bit like a spreadsheet dump, but it is not CSV, not OFX, and not QFX. Headers such as !ACCNT or !TRNS define record types; columns are tab-oriented in classic IIF.

Converting IIF to CSV is for review, cleanup, migration analysis, and audit — not because QuickBooks Online expects IIF. US and Canadian Desktop users hit this workflow constantly; UK and Australian firms migrating off Desktop also need readable tables before mapping to Xero or QBO.

IIF vs QFX vs CSV

Pick the right tool for the file you actually have.

What an IIF File Looks Like

IIF files are plain text. Section headers start with ! and declare columns; data rows use the matching keyword without !.

!ACCNT	NAME	ACCNTTYPE	DESC
ACCNT	Office Supplies	EXP	Consumables
ACCNT	Sales	INC	Product sales
!TRNS	TRNSTYPE	DATE	ACCNT	NAME	AMOUNT	MEMO
!SPL	TRNSTYPE	DATE	ACCNT	NAME	AMOUNT	MEMO
!ENDTRNS
TRNS	GENERAL JOURNAL	05/03/2026	Office Supplies		-42.18	Paper
SPL	GENERAL JOURNAL	05/03/2026	Cash		42.18	Paper
ENDTRNS

Step-by-Step: IIF → CSV

Use this path when you need a spreadsheet view.

• Export or obtain the .iif from QuickBooks Desktop (or a partner system that emits IIF).
• Open IIF to CSV in the Finance File Converter on Convert CSV Online.
• Preview rows — confirm account names, dates, and amounts look sane.
• Download CSV and optionally convert to Excel for stakeholder review.
• Clean duplicates, fix account naming, and document mappings.
• If the destination is still QuickBooks Desktop, re-import a corrected IIF (not the CSV) unless you use a supported CSV import path.
• If the destination is QBO/Xero/another ledger, map CSV columns into that product’s template.

record_type,date,account,name,amount,memo
TRNS,2026-05-03,Office Supplies,,-42.18,Paper
SPL,2026-05-03,Cash,,42.18,Paper

When to Convert to CSV vs Keep IIF

Conversion is a review tool. Import rules still belong to QuickBooks.

Dates and Locales in IIF

IIF date text often reflects the Desktop company’s locale — US MM/DD/YYYY is common in US company files; other regions may differ.

• After conversion, normalize dates before feeding another country’s system.
• UK/AU migrations should not assume US month-first IIF dates.
• Prefer ISO dates in intermediate CSV used for multi-country teams.
• Watch Excel: opening the CSV can swap days 1–12 again.

Transaction Structure: TRNS, SPL, ENDTRNS

QuickBooks transactions are balanced bundles. A TRNS header line plus SPL split lines must net correctly.

• Do not delete SPL rows in CSV without adjusting the balancing account.
• Amount signs must still balance when you reassemble imports.
• Inventory, payroll, and sales tax splits are easy to break with casual spreadsheet edits.
• For complex files, use CSV to find problems, then correct inside QuickBooks or with a validated IIF rebuild process.

Common IIF Problems Visible in CSV

Conversion shines a light on issues Desktop would reject later.

• Account names that do not exist in the target company file.
• Customer/vendor names that will create duplicates.
• Empty required fields on list rows.
• Unbalanced journal amounts after manual edits.
• Mixed encodings if the IIF was edited in a non-Unicode tool.
• Confusion between IIF and QFX — wrong converter yields empty or nonsense tables.

Security and Client Data

IIF exports can contain full general-ledger detail.

• Treat IIF like a financial database dump.
• Prefer browser-side conversion for routine review.
• Clear downloads on shared bookkeeping PCs.
• Share converted CSV only with people who already have ledger access.

Common Mistakes

Frequent mix-ups.

• Renaming .iif to .csv and hoping Excel understands it.
• Uploading IIF into QuickBooks Online bank CSV tools.
• Editing balanced transactions in CSV and expecting Desktop to accept the CSV as IIF.
• Using an OFX/QFX converter on an IIF file.
• Merging multiple IIF sections into one sheet without a record_type column.

Best Practices

Keep the native format for import; use CSV for visibility.

• Archive the original IIF alongside any CSV you generate.
• Convert → review → decide (Desktop IIF vs QBO/Xero CSV templates).
• Validate totals: sum of amounts in CSV vs trial balance expectations.
• Document column mappings for migrations out of Desktop.
• Train staff that IIF ≠ bank download.

Why Use Convert CSV Online?

Convert CSV Online is free, browser-based, and requires no account for everyday conversions. The Finance File Converter’s IIF to CSV and IIF to Excel tools turn Desktop interchange files into rectangular tables you can audit. Pair with the Online CSV Editor for cleanup before migration mapping. Works on Windows, macOS, and Linux browsers for US, Canadian, UK, and Australian bookkeeping teams.

Conclusion

IIF to CSV unlocks readable QuickBooks Desktop data without pretending CSV is IIF. Convert for inspection and migration planning; import with the format your target product actually supports.