Identify Any Financial
File Format

Why You Need a Financial File Format Detector

Financial data comes in dozens of formats, each with its own structure, encoding, and compatibility requirements. Whether you downloaded a bank statement, received an export from your accountant, or found an old backup file, knowing the exact format is the critical first step before you can import, convert, or analyze the data. The Financial File Format Detector eliminates the guesswork by analyzing file content, magic bytes, headers, and structural patterns to identify the format with a confidence score — all entirely within your browser with zero server uploads.

Misidentifying a financial file format leads to failed imports, data corruption, and wasted time. A .qbo file that is actually an OFX file without the INTU.BID tag will be rejected by QuickBooks. A CSV file with semicolons instead of commas will produce garbled columns in Excel. An MT940 file from a European bank will look like gibberish if opened as plain text. The detector solves all of these problems by telling you exactly what you have and recommending the right conversion tool.

QBO vs OFX: Understanding the Difference

One of the most frequently asked questions in QuickBooks forums is “what is the difference between QBO and OFX files?” Both formats share the same underlying SGML (Standard Generalized Markup Language) structure developed by the Open Financial Exchange consortium in 1997. They contain identical transaction data — dates, amounts, payee names, transaction types, account IDs, and memo fields. The critical difference is a single tag: <INTU.BID>.

QBO (QuickBooks Web Connect) files include the INTU.BID tag within the signon response block. This tag contains an Intuit-assigned financial institution identifier that tells QuickBooks which bank profile to associate with the import. Without this tag, QuickBooks Desktop will display “This file is not a valid Web Connect file” and QuickBooks Online will fail to process the import. Our detector specifically checks for this tag to distinguish QBO from standard OFX files, and our OFX to QBO Converter adds the tag automatically.

QFX Files: The Quicken Variant

QFX (Quicken Financial Exchange) files are another OFX variant, specifically designed for Intuit's Quicken software. Structurally, QFX files are nearly identical to QBO files — they contain the same SGML transaction data and often include theINTU.BID tag. The primary difference is the file extension (.qfx vs .qbo) and the intended target application. The detector identifies QFX files by the .qfx extension combined with OFX structural markers. If you need to convert a QFX file for QuickBooks, use the QFX to QBO Converter.

Detecting IIF (Intuit Interchange Format) Files

IIF is Intuit's legacy tab-delimited format used exclusively by QuickBooks Desktop (Pro, Premier, and Enterprise). IIF files are immediately recognizable by their header lines that start with exclamation marks: !TRNS for transaction headers,!SPL for split line headers, and !HDR for file headers. Transaction groups are terminated by ENDTRNS on a line by itself.

The detector achieves very high confidence (98%) when all three markers are present —!TRNS, !SPL, and ENDTRNS — since no other financial format uses this combination. For working with IIF files, PrimeConnect offers the IIF Viewer & Validator for previewing files, the IIF to QBO Converter for upgrading to Web Connect format, and the IIF to CSV Converter for spreadsheet exports.

QIF (Quicken Interchange Format) Detection

QIF is one of the oldest financial interchange formats, created by Intuit for Quicken in the early 1990s. QIF files are plain text and start with a !Type: header that identifies the account type — Bank, CCard (credit card), Cash, Oth A (other asset), Oth L (other liability), or Invst (investment). Individual transactions are separated by a caret (^) on its own line, with single-letter field codes: D for date, T for amount, P for payee, M for memo, N for check number, and L for category.

Despite being largely superseded by OFX, QIF files are still encountered when migrating from older software or processing historical data. The detector identifies QIF by the!Type: header and caret separators. Convert QIF files with our QIF to QBO Converter, QIF to CSV Converter, or QIF to IIF Converter.

How CSV Format Detection Works

CSV (Comma-Separated Values) is the most common file format for bank transaction exports, but “CSV” is misleading — many banks use semicolons, tabs, or other delimiters. The detector uses a multi-step approach to identify CSV files:

1. Delimiter detection — Counts occurrences of commas, semicolons, and tabs in the first row to identify the most likely delimiter.
2. Consistency check — Verifies that the delimiter count is consistent across multiple rows, confirming a tabular structure rather than random text.
3. Financial keyword scanning — Searches the header row for financial terms like “date”, “amount”, “debit”, “credit”, “balance”, and “transaction” to confirm the data is financial in nature.
4. Extension confirmation — The .csv, .tsv, or .txt extension provides an additional confidence boost.

Once identified, use the CSV to QBO Converter for QuickBooks Online, the CSV to IIF Converter for QuickBooks Desktop, or the CSV to OFX Converter for OFX-compatible applications. For messy bank exports, the Bank CSV Cleaner can standardize formatting before conversion. Use the Duplicate Detector to find and remove duplicate transactions in your CSV files.

MT940 and CAMT.053: European Bank Statement Formats

MT940 is the SWIFT (Society for Worldwide Interbank Financial Telecommunication) standard for electronic bank statements, used extensively by European banks and many international financial institutions. MT940 files use a distinctive colon-delimited tag structure::20: for transaction references, :25: for account identification (often IBAN), :60F: for opening balance, :61: for individual transactions, and :86: for transaction descriptions. The detector identifies MT940 with 98% confidence when all four core tags are present.

CAMT.053 (Cash Management) is the ISO 20022 replacement for MT940, using XML instead of the legacy SWIFT tag format. CAMT.053 files are identified by the namespace URIurn:iso:std:iso:20022:tech:xsd:camt.053 within the XML declaration. The detector checks for this namespace along with the <BkToCstmrStmt>root element. Convert these formats with the MT940 to QBO Converter, MT940 to CSV Converter, or CAMT.053 to QBO Converter.

Binary Format Detection: XLSX and PDF

Unlike text-based formats, XLSX and PDF files cannot be analyzed by reading their content as plain text. Instead, the detector relies on “magic bytes” — the first few bytes of the file that serve as a unique format signature:

• PDF files always begin with the bytes %PDF (hex: 25 50 44 46). The detector also extracts the PDF version number from the header (e.g., PDF 1.7 or 2.0). Convert PDF bank statements with our PDF to QBO Converter, which uses AI-powered extraction to identify transaction tables within PDF documents.
• XLSX files are ZIP archives (starting with PK, hex: 50 4B) containing XML workbook data. The detector combines the ZIP magic bytes with the .xlsx file extension for high-confidence identification. Import Excel files with the XLSX to QBO Converter.

Common Use Cases for Format Detection

The Financial File Format Detector is invaluable in several real-world scenarios:

• Unknown bank exports — Your bank gave you a file with an ambiguous extension or no extension at all. The detector analyzes the content to identify the actual format regardless of the filename.
• Migration between accounting software — Moving from Quicken to QuickBooks? The detector identifies whether your exported files are QIF, QFX, or OFX, and recommends the appropriate conversion path.
• Troubleshooting import failures — QuickBooks keeps rejecting your file? The detector reveals whether the file is actually the format you think it is. A file labeled .qbo might actually be plain OFX without the required INTU.BID tag. Use our Import Troubleshooter for deeper analysis.
• International bank statements — Banks in Europe and Asia often provide MT940 or CAMT.053 files that are unfamiliar to US-based users. The detector identifies these formats and points you to the right converter.

Working with Payment Platform Exports

Beyond traditional bank formats, PrimeConnect offers specialized converters for major payment platforms. While the format detector identifies the underlying file format (typically CSV), these platform-specific tools handle the unique column layouts and data structures used by each provider:

• Stripe to QuickBooks Converter — Convert Stripe payment exports with proper fee handling and payout mapping.
• PayPal to QuickBooks Converter — Convert PayPal activity reports with currency conversion and fee separation.
• Square to QuickBooks Converter — Convert Square POS transaction exports to QuickBooks-ready format.
• Amazon to QuickBooks Converter — Convert Amazon Seller Central reports to QuickBooks CSV format.
• Shopify to QuickBooks Converter — Convert Shopify payout reports to QuickBooks-compatible format.
• Etsy to QuickBooks Converter — Convert Etsy shop financial exports to QuickBooks CSV format.

Complete Free Accounting Tools Suite

The Financial File Format Detector is part of PrimeConnect's complete suite of free QuickBooks conversion and utility tools. Once you identify your file format, use the appropriate tool to convert, view, or clean your data:

• CSV to IIF Converter — Convert bank CSV files to QuickBooks Desktop IIF format.
• CSV to QBO Converter — Convert bank CSV files to QBO Web Connect format.
• QBO to IIF Converter — Convert QBO files to QuickBooks Desktop IIF format.
• IIF to QBO Converter — Upgrade legacy IIF files to QBO Web Connect format.
• PDF to QBO Converter — Extract transactions from PDF bank statements.
• IIF Viewer & Validator — Preview and validate IIF files before import.
• Bank CSV Cleaner — Clean messy bank CSV exports.
• Chart of Accounts Generator — Generate industry-specific chart of accounts.
• OFX to QBO Converter — Convert OFX bank files to QuickBooks QBO format.
• QFX to QBO Converter — Convert Quicken QFX files to QuickBooks QBO format.
• QBO to CSV Converter — Export QBO transactions to CSV spreadsheets.
• OFX to CSV Converter — Convert OFX files to CSV for Excel and Google Sheets.
• OFX to IIF Converter — Convert OFX files to QuickBooks Desktop IIF format.
• CSV to OFX Converter — Transform bank CSV exports into standard OFX format.
• QIF to QBO Converter — Upgrade legacy Quicken QIF files to QBO format.
• QBO to PDF Converter — Generate professional PDF statements from QBO files.
• MT940 to QBO Converter — Convert SWIFT MT940 bank statements to QBO format.
• QIF to CSV Converter — Export QIF files to CSV spreadsheets.
• QIF to IIF Converter — Convert QIF files to QuickBooks Desktop IIF format.
• IIF to CSV Converter — Export IIF files to CSV for spreadsheets.
• QBO to OFX Converter — Convert QBO files back to standard OFX format.
• MT940 to CSV Converter — Export MT940 bank statements to CSV spreadsheets.
• QBO Viewer — Preview and inspect QBO file contents.
• OFX Viewer — Preview and inspect OFX file contents.
• XLSX to QBO Converter — Convert Excel spreadsheets to QBO format.
• Etsy to QuickBooks Converter — Convert Etsy financial exports to QuickBooks CSV.
• Duplicate Detector — Find and remove duplicate transactions.
• Import Troubleshooter — Diagnose and fix QuickBooks import failures.
• CAMT.053 to QBO Converter — Convert ISO 20022 bank statements to QBO format.
• Stripe to QuickBooks Converter — Convert Stripe payment exports to QuickBooks CSV.
• PayPal to QuickBooks Converter — Convert PayPal activity to QuickBooks CSV.
• Square to QuickBooks Converter — Convert Square POS exports to QuickBooks CSV.
• Amazon to QuickBooks Converter — Convert Amazon Seller reports to QuickBooks CSV.
• Shopify to QuickBooks Converter — Convert Shopify payouts to QuickBooks CSV.