YNAB 4 Bank CSV Converter

A lightweight, non-destructive Python utility to transform bank CSV export files into the exact format required for import into YNAB 4 (You Need a Budget).

Features

• Non-Destructive: Reads your original bank export and writes out a brand-new, correctly structured CSV file without modifying your source data.
• Automatic Date Conversion: Transforms bank date formats (YYYY/MM/DD) into YNAB 4 compatible formats (MM/DD/YY).
• Column Mapping: Automatically maps bank descriptions to Payee, debits to Outflow, and credits to Inflow, while supplying the necessary blank columns (Category, Memo).
• Command-Line Interface: Easily run from the terminal with customizable input and output paths.

Prerequisites

Make sure you have Python installed along with the pandas library.

pip install pandas

Usage

Save the script as ynab_convert.py and run it from your terminal by providing the path to your bank's CSV export:

python ynab_convert.py path/to/your/bank_export.csv

Options

• -o, --output: Specify a custom path for the output file (default is YNAB_Import_Ready.csv).

Example:

python ynab_convert.py my_bank_data.csv -o custom_ynab_import.csv

Column Mapping Reference

YNAB 4 Sample Column	Bank CSV Source	Action / Transformation
Date	Value Date	Converted from YYYY/MM/DD to MM/DD/YY
Payee	Description	Mapped directly
Category	None	Left blank
Memo	None	Left blank
Outflow	Debit	Mapped directly
Inflow	Credit	Mapped directly
N/A	Balance	Dropped (not required by YNAB 4)