GUIDE · CSV TO OFX
To convert CSV to OFX, wrap each row in an STMTTRN record (TRNTYPE, a YYYYMMDD date, a signed amount, a unique FITID and a NAME), then add the header, account block and closing balance. First check whether your software takes CSV; most do. ZeraBooks Convert makes QuickBooks-ready and Xero-ready CSV from PDFs; see the bank statement converter.
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FIELD BY FIELD
Bank CSVs differ, but most have a date, a description, the amount in one or two columns and sometimes a running balance. Here is where each goes in an OFX file, whose layout is explained in what is an OFX file.
| CSV column | OFX element | Rule |
|---|---|---|
| Date (10/02/2026) | DTPOSTED | Year first, no separators: 20261002 |
| Description | NAME | 32 characters at most; put any overflow in MEMO |
| Debit (212.48) | TRNAMT | Written negative: -212.48 |
| Credit (1,860.00) | TRNAMT | Written positive, no thousands comma: 1860.00 |
| Debit or Credit | TRNTYPE | DEBIT or CREDIT to match; the sign still rules |
| Check number, if any | CHECKNUM | Up to 12 characters |
| Balance (last row) | LEDGERBAL › BALAMT and DTASOF | Only the final balance goes in; the running column is dropped |
| (none) | FITID | Invent one per row, unique and stable |
| (none) | BANKID, ACCTID, ACCTTYPE, CURDEF | From your account details; ACCTTYPE is CHECKING, SAVINGS, MONEYMRKT, CREDITLINE or CD |
| (none) | DTSTART, DTEND | First and last dates in the CSV |
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THE CSV
Tidewater Yoga Studio is a fictional studio. Its bank exports October 2 to 14, 2026 like this, with debits and credits in separate columns:
| Date | Description | Debit | Credit | Balance |
|---|---|---|---|---|
| 10/01/2026 | Opening balance | 3515.27 | ||
| 10/02/2026 | STUDIO PAYOUT 4471 | 1860.00 | 5375.27 | |
| 10/05/2026 | CITY POWER AND LIGHT | 212.48 | 5162.79 | |
| 10/09/2026 | MAT CLEANING SUPPLY | 64.10 | 5098.69 | |
| 10/14/2026 | STUDIO PAYOUT 4471 | 1420.00 | 6518.69 | |
| Totals | 276.58 | 3280.00 | 6518.69 |
The check before converting: 3,515.27 + 3,280.00 − 276.58 = 6,518.69, the last balance. If the running balance doesn’t agree with the debits and credits, a row is missing, and an OFX built from it will carry the gap into your books.
THE OFX
The same data as an OFX 2.x file, which is XML, so every element closes. The header and sign-on block are shortened.
| Line in the file | From the CSV? |
|---|---|
| <?xml version="1.0" encoding="UTF-8"?> <?OFX OFXHEADER="200" VERSION="220" SECURITY="NONE" OLDFILEUID="NONE" NEWFILEUID="NONE"?> | No, fixed text |
| <OFX><SIGNONMSGSRSV1><SONRS><STATUS><CODE>0</CODE><SEVERITY>INFO</SEVERITY></STATUS><DTSERVER>20261015080000</DTSERVER><LANGUAGE>ENG</LANGUAGE></SONRS></SIGNONMSGSRSV1> | No, required sign-on block |
| <BANKMSGSRSV1><STMTTRNRS> … <STMTRS><CURDEF>USD</CURDEF> | No, typed in |
| <BANKACCTFROM><BANKID>123456789</BANKID><ACCTID>3398120476</ACCTID><ACCTTYPE>CHECKING</ACCTTYPE></BANKACCTFROM> | No, typed in |
| <BANKTRANLIST><DTSTART>20261002</DTSTART><DTEND>20261014</DTEND> | Yes, first and last dates |
| <STMTTRN><TRNTYPE>CREDIT</TRNTYPE><DTPOSTED>20261002</DTPOSTED><TRNAMT>1860.00</TRNAMT><FITID>20261002-01</FITID><NAME>STUDIO PAYOUT 4471</NAME></STMTTRN> | Row 2, FITID invented |
| <STMTTRN><TRNTYPE>DEBIT</TRNTYPE><DTPOSTED>20261005</DTPOSTED><TRNAMT>-212.48</TRNAMT><FITID>20261005-01</FITID><NAME>CITY POWER AND LIGHT</NAME></STMTTRN> | Row 3 |
| <STMTTRN><TRNTYPE>DEBIT</TRNTYPE><DTPOSTED>20261009</DTPOSTED><TRNAMT>-64.10</TRNAMT><FITID>20261009-01</FITID><NAME>MAT CLEANING SUPPLY</NAME></STMTTRN> | Row 4 |
| <STMTTRN><TRNTYPE>CREDIT</TRNTYPE><DTPOSTED>20261014</DTPOSTED><TRNAMT>1420.00</TRNAMT><FITID>20261014-01</FITID><NAME>STUDIO PAYOUT 4471</NAME></STMTTRN></BANKTRANLIST> | Row 5 |
| <LEDGERBAL><BALAMT>6518.69</BALAMT><DTASOF>20261014</DTASOF></LEDGERBAL> | Yes, last Balance |
| </STMTRS></STMTTRNRS></BANKMSGSRSV1></OFX> | No, closing tags |
The opening-balance row isn’t a transaction, so it has no STMTTRN; OFX has no place for an opening balance at all. The four amounts net to 1,860.00 − 212.48 − 64.10 + 1,420.00 = 3,003.42, and 3,515.27 + 3,003.42 = 6,518.69, the LEDGERBAL.
GET IT RIGHT
Most failed imports come down to one of these. They are set by the OFX specification, not by any one program.
Sign-on needs STATUS, DTSERVER and LANGUAGE. The statement needs CURDEF, the account block and LEDGERBAL. Each transaction needs TRNTYPE, DTPOSTED, TRNAMT and FITID.
An XML header with XML tags that all close, or the old OFXHEADER:100 lines with SGML. Mixing the two breaks the file.
Money out is negative and money in positive. On a credit card, a purchase is negative and a payment positive. TRNTYPE doesn’t change the effect.
Up to 255 characters, never repeated in the account, and the same every time the same row is converted. Date plus a sequence within the day, as above, stays stable as long as the bank keeps its row order.
NAME 32 characters, CHECKNUM 12, BANKID 9, ACCTID 22. Longer values can be cut or rejected.
No currency signs, no thousands commas, a period for decimals.
FREE ROUTES
Checked against each project’s own documentation on October 22, 2026. Start with the first row: it often makes the rest unnecessary.
| Route | What it does | Note |
|---|---|---|
| Import the CSV directly | QuickBooks Online, Xero and GnuCash all import CSV bank files | No OFX needed; GnuCash uses File › Import › Import Transactions from CSV |
| csv2ofx (open source, MIT License) | Command-line tool and Python library: csv2ofx -m <mapping> source.csv dest.ofx | Needs a column mapping for your bank’s CSV; -L lists the built-in ones |
| ofxtools (Python library) | Writes OFX 1.x (SGML) or 2.x (XML) from Python | Python 3.10 or later; you write the script |
| By hand in a text editor | Copy the sample above and replace the values | Fine for a few rows; easy to break a tag |
GnuCash reads OFX but exports only CSV, so it can’t write an OFX for you. Quicken looks for the QFX flavour with Intuit’s bank ID, so a homemade OFX may be refused there whatever tool made it.
WHAT CHANGES
Two things are lost. The running balance shrinks to a single closing figure, and the opening balance disappears entirely, because OFX has no element for it. Any extra columns your bank added, such as a category or a branch, have nowhere to go unless you squeeze them into MEMO.
Two things are made up. The FITIDs are yours, not the bank’s, so a real download from the bank for overlapping dates won’t match them and can import the same transactions twice. The account block is whatever you typed. Nothing in a converted OFX is more accurate than the CSV it came from; it is the same data in a stricter wrapper.
SKIP THE OFX
ZeraBooks Convert doesn’t read CSV and doesn’t make OFX, QFX, QBO or QIF files. It reads PDF statements and downloads the CSV your accounting software already imports.
READY FOR YOUR SOFTWARE
Pick the format for where the file is going and the columns, signs and US dates are already right. Xero-ready gives Date, Amount, Payee, Description and Reference; the steps for Xero are in bank statement to Xero. For a plain spreadsheet, see convert a bank statement to CSV.
Choose a download formatPROVEN BEFORE DOWNLOAD
A PDF statement prints the opening and closing balance, which an OFX can’t hold. Convert checks every account against both, to the cent, so the 3,515.27 to 6,518.69 check above happens before you download. A statement that doesn’t tie is flagged with the difference.
How Convert proves a statementMORE FILE FORMATS
No. An OFX file is tagged text with a header, an account block and one STMTTRN per transaction. A renamed CSV has none of that, and any program expecting OFX will reject it. The same is true of a .qbo file; see how to convert CSV to QBO format.
No. Both import CSV bank files as well as OFX. Converting a CSV to OFX for them adds work without adding information.
Use something unique within the account that won’t change if you convert the same CSV again, such as the date plus a sequence number within that day: 20261002-01, 20261002-02. Never use a random number; it changes every run and causes duplicates.
The FITIDs changed between runs, or a real bank download overlapped your homemade file. Software skips only FITIDs it has already seen. Delete the duplicates in the software, and keep one source per date range.
No. ZeraBooks Convert reads PDF statements and downloads Excel or CSV only; it doesn’t make OFX, QFX, QBO or QIF files. Most accounting software, including QuickBooks Online and Xero, imports its CSV formats directly. To go the other way with a card download, see QFX to CSV.
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ZeraBooks Convert reads PDF statements, proves every account to the cent and downloads QuickBooks-ready, Xero-ready or Sage-ready CSV. 7-day trial, then $79 a month billed annually; see ZeraBooks pricing.
Last updated October 22, 2026 · Written by Damin Mutti, founder of ZeraBooks