OFX

Lightweight .NET 10 library for parsing OFX bank statement files. Handles both OFX 2.x XML and OFX 1.x SGML formats (including files exported by South African banks such as ABSA and FNB). Extracts statements, accounts, transactions, and balances — without the overhead of a full OFX stack.

Specifications

The implementation is aligned with two specifications:

• OFX Banking Specification v2.3 (October 2020, Financial Data Exchange) — used as the primary reference for element names, data types, transaction type values, and account type values.
• FNB File Specification: Statement Type OFX (July 2012, First National Bank) — used as the bank-specific reference for the exact fields, field lengths, and data formats produced by South African banks.

Requirements

• .NET 10

File Format Support

The parser handles both OFX file formats:

Format	Version	Detection
OFX 2.x XML	Standard XML	File starts with <OFX>
OFX 1.x SGML	Used by FNB / ABSA	File starts with OFXHEADER:100

OFX 1.x SGML files are automatically converted to well-formed XML before parsing.

Supported OFX Elements

Element	Description
STMTRS	Statement currency and account details
BANKACCTFROM	Bank account identifier (BANKID, ACCTID, ACCTTYPE)
BANKTRANLIST	Transaction list with DTSTART / DTEND
STMTTRN	Individual transactions — all 18 OFX TRNTYPE values, FITID, NAME, MEMO, CHECKNUM, REFNUM
LEDGERBAL	Ledger balance and date
AVAILBAL	Available balance and date (optional)

Solution Structure

Ofx.slnx                   ← solution file
Ofx/                       ← library project
  Ofx.csproj
  ITransactionParser.cs
  TransactionParser.cs
  Configuration/
  Repository/
Ofx.Tests/                 ← xUnit test project
  Ofx.Tests.csproj
  TransactionParserXmlTests.cs
  TransactionParserSgmlTests.cs
docs/                      ← specification docs and sample OFX files
README.md

Usage

ITransactionParser parser = new TransactionParser("statement.ofx");
Statement? statement = parser.ElectronicStatement;

Testing

The Ofx.Tests project validates the parser against two sample files in docs/samples/:

Sample file	Format	What it covers
ofx-sample-2.3.xml	OFX 2.3 XML	Checking account with 13 transactions; full datetime format; XML entity decoding (& → &); CORRECTACTION=REPLACE; ORIGCURRENCY; nested BANKACCTTO; ledger and available balances
ofx-sample-1x.ofx	OFX 1.x SGML	Checking account with 9 transactions; date-only format (YYYYMMDD); raw & in leaf values (escaped during SGML-to-XML conversion); nested BANKACCTTO aggregate

Run via the solution (builds both projects):

dotnet test

Or target the test project directly:

dotnet test Ofx.Tests/Ofx.Tests.csproj