BankClean turns the CSV you download from your UK bank into a clean, consistent table inside Google Sheets™, then helps you sort it into the boxes on the Self-Assessment forms.

WHAT IT DOES
- Cleans bank CSV exports from major UK banks, building societies and app banks into one layout: ISO date, description, signed amount, balance, bank and the original source row.
- Understands UK dates (day first), pound signs, thousands separators, separate debit and credit columns, and statements that start with extra header lines.
- Spots overlapping statements: re-import a file and rows already on your sheet are skipped. Genuine repeat purchases are kept and flagged.
- Checks running balances where your bank provides them, so gaps in the data are flagged.
- Maps each transaction to a Self Assessment category using an editable rules sheet (keyword to category). Longest matching keyword wins, you can use simple regular expressions, and you can override any single row.
- Summarises totals per category for each UK tax year (6 April to 5 April), using the box names from the SA103 full self-employment form, with an SA105 UK property section for landlords.

HOW IT WORKS
1. Open Extensions > BankClean > Open BankClean.
2. Choose your CSV file (or use data already in the sheet) and let BankClean detect the bank.
3. Review the Clean sheet, tweak the Rules sheet, and build the summary.

PRIVATE BY DESIGN
BankClean only works with the spreadsheet you have open. Your transactions stay in your spreadsheet: they are not sent to TurboKast or anyone else, and the add-on makes no network requests.

FREE WITH PAID FEATURES
Free: clean and categorise up to 100 transactions with SA103 (self-employed) categories.
Pro licence key (one-off £19 from our online store): unlimited transactions and SA105 property categories.

GOOD TO KNOW
- Box numbers follow the 2025-26 SA103F and SA105 forms; check them against the form for your tax year. BankClean prepares your records and is not tax or accounting advice.
- Bank export layouts change. If a layout is not recognised you can still map it by choosing "Other / generic", and the sidebar tells you when a layout has not been checked against a real export.
- BankClean is not affiliated with, or endorsed by, HMRC, Google or any bank.

Support: support@turbokast.com

Google Sheets™ is a trademark of Google LLC.