Bank CSV categoriser
Drop in a bank export and get your income and expenses sorted into categories, a rough tax pot and a summary to download. It all happens in your browser, and you can check that nothing is sent.
Your bank file
About you
A job, pension or anything else that uses up your allowance first. Leave 0 if none.
Only affects the quarterly breakdown. Under Making Tax Digital you choose standard or calendar quarters.
Chosen from your file. Change it if the file spans two years.
Prove nothing leaves your device
This page has a rule built into it that your browser enforces: it is not allowed to send anything anywhere
(a connect-src 'none' content security policy), and the page has no newsletter form and no analytics.
Don't take our word for it. Check:
- Open your browser's developer tools (F12, or Cmd+Option+I on a Mac) and go to the Network tab.
- Clear it, then drop in your bank file. Nothing appears. Not one request.
- For the strict version, turn on aeroplane mode (or unplug the cable) before you drop the file in. It still works.
Requests made by this page while it read your file: 0. (Counted by your browser, not by us. Dropped files are held in memory only, and closing the tab discards them.)
Your year at a glance
and aren't counted until you choose one.
Check the categories
Categories are guessed from words in the description, with simple rules and no AI. They will be wrong sometimes. Fix any row; the totals above update as you go.
Save it
The paid pack adds a full Excel workbook (every row, editable categories that update the totals), the category-by-month pivot and the quarterly breakdown below, as one file that works offline. The blurred previews show your own numbers.
Category by month
Quarterly breakdown
The quarterly view is a record in the shape quarterly updates use. It does not send anything to HMRC: that needs HMRC-recognised software.
Export your transactions from your bank's website or app as CSV, drop the file in, and the tool reads the date, description and amount columns (whatever the bank calls them), puts each row in a category using keyword rules, and adds it up for the tax year. Money in that matches words like Etsy, Stripe or PayPal is counted as sales; money out is matched against software, postage, fuel, fees and so on. Transfers to savings, HMRC payments and obvious personal shopping are left out of the totals. Anything it can't place is put in 'Needs a category' for you to decide.
The tax pot is deliberately rough. It takes profit (income minus expenses), applies the 2025/26 and 2026/27 England, Wales and Northern Ireland income tax bands with the standard personal allowance, and for a sole trader adds Class 4 National Insurance. It assumes no other income unless you enter some. It does not know about the trading allowance, capital allowances, losses, student loans, pension relief, payments on account or Scottish rates.
Bank exports differ and banks change them, so the column matching is by name rather than position and the first thing shown is how many rows were read. Check that against your statement before you rely on any total.
Is my bank data uploaded anywhere?
No. The file is read by your own browser and held in memory only. The page tells your browser not to allow any outgoing connections at all, and has no analytics or sign-up form, so you can watch the Network tab in developer tools stay empty. Closing the tab discards the data.
Which banks work?
Any export with a date, a description and an amount (or separate paid in and paid out columns). We've built for Monzo, Starling, Barclays, HSBC, Lloyds, NatWest, Santander and Tide. Banks don't publish their export layouts, so if yours isn't read correctly, tell us the header row (no transactions) and we'll add it.
How accurate are the categories?
They're guesses from keywords, good on common payees and poor on one-off names, so always look at 'Needs a category' and skim the list. You decide the final category on every row.
Is the tax pot right?
It's a rough planning number, not your tax bill. It ignores things that can change the figure a lot, such as the trading allowance, capital allowances, other income you haven't entered, and Scottish rates. Use it to decide roughly how much to set aside, and check your real position on GOV.UK or with an accountant.
Does this send anything to HMRC?
No. Nothing is filed or sent to HMRC. Making Tax Digital quarterly updates have to be sent through HMRC-recognised software. The quarterly breakdown here is a record to help you prepare.
Is this tax advice?
No. It's an estimate to help you plan, not financial or tax advice, and we are not accountants.
Everything happens in your browser. Nothing you type or add is uploaded to us or anyone else, and the tool works with no account.
An estimate to help you plan, not financial or tax advice. Nothing is filed or sent to HMRC. Built with AI assistance and finished by a human. Check figures before you rely on them.