IIF to CSV Converter: Complete Feature Guide & Reference
📄 Open the IIF to CSV Converter to try every feature described in this guide.
Open IIF to CSV Converter →Contents
What Is the IIF to CSV Converter?
The FinancialDataTools.com IIF to CSV Converter is a free, browser-based tool that transforms QuickBooks Intuit Interchange Format (IIF) files into standard Comma-Separated Values (CSV) format. All processing runs entirely inside your browser tab — no file is ever transmitted to any server.
The converter is built for bookkeepers, accountants, and financial analysts who need to extract data from QuickBooks IIF exports and work with it in Excel, Google Sheets, or any other tool that reads CSV files.
Try the IIF to CSV Converter — runs entirely in your browser and never uploads your files.
Open the Converter →About the IIF Input Format
IIF (Intuit Interchange Format) is a tab-delimited text format used by QuickBooks to import and export financial data. IIF files contain one or more record types — such as transactions (TRNS), split lines (SPL), accounts (ACCNT), customers (CUST), vendors (VEND), and more.
Each record type is defined by a header line beginning with ! (for example, !TRNS) that lists the field names for that record type. Data lines use the same record type name without the ! prefix. Transaction blocks are closed with ENDTRNS lines.
The converter accepts IIF files (.iif) and plain-text files (.txt) that follow the IIF structure. No pre-processing is required before loading.
About the CSV Output Format
The converter produces a flat CSV file containing all records from across the IIF file. A TYPE column is added as the first column to identify each row's record type (for example, TRNS, SPL, or ACCNT). The remaining columns are the union of all field names encountered across all record types in the file.
Fields that do not exist for a given record type are left empty in the corresponding CSV row. This unified flat layout makes the data easy to filter and analyse in any spreadsheet application.
The Toolbar
The toolbar across the top provides all primary actions for the conversion workflow. Use Open to browse for your IIF file, or drag and drop the file onto the source panel. Once a file is loaded, click Convert to CSV to generate the output. Click Export CSV to download the result. The Reset button clears all state for a new conversion.
Source (IIF) Panel
The left panel shows your loaded IIF data as a table preview. Each row represents one parsed IIF record, with the TYPE column appearing first. For large files, the preview is capped at 500 rows — a notice is shown if your file exceeds this limit. The full dataset is always converted regardless of the preview cap.
Output (CSV) Panel
The right panel displays the converted CSV output as plain text. Before conversion it shows a placeholder. After clicking Convert to CSV, the panel renders the full CSV content. The panel is scrollable for any file size.
Output File Naming
The downloaded CSV file is named to match your input file — only the extension is changed to .csv. A file named transactions.iif produces transactions.csv. This keeps your file set organised without requiring any renaming.
Privacy & Security
The IIF to CSV Converter is built privacy-first. Your file is parsed and converted entirely inside your browser tab using JavaScript — no file content is ever transmitted to any server. This makes the converter appropriate for sensitive financial data including QuickBooks transaction exports, chart-of-accounts data, and customer or vendor records.
Closing the browser tab clears all data from memory. No data is written to localStorage or any persistent browser storage.
Use Cases for Financial Data
Converting IIF to CSV is a common step when working with QuickBooks data outside the QuickBooks environment. Typical scenarios include opening QuickBooks transaction exports in Excel for analysis, importing historical accounting data into a new system that requires CSV input, sharing transaction records with a counterparty or auditor in a universally readable format, and archiving QuickBooks data in a format that does not require QuickBooks to open.