How do I sort a bank export into categories for my bookkeeping?

At the end of the month you have a bank export with a hundred lines and a bookkeeper waiting. Most of the lines are obvious: the software subscription, the train ticket, the card fees. A few are not: a payment to a person, a supermarket, a name you do not recognise. Sorting them by hand is tedious and getting one wrong is easy.

The sensible approach is to group the rows by merchant, so you decide once per merchant and not once per row, and to be strict about the unclear ones. A guess that lands in the wrong category is worse than a blank, because nobody looks at it again.

What you need

• Your bank or card export as text. Remove account numbers before pasting. You only need the date, the description and the amount.
• Your list of categories, if your bookkeeper gave you one. If not, the assistant proposes a short list.
• A line on the kind of business you run, so a name like "Adobe" makes sense.

The prompt

Paste this into a new chat, then paste your rows.

I want a bank export categorised for bookkeeping. Work only from the rows below. Never invent a transaction or change an amount.

1. Group the rows by merchant name and give each group a count and a total.
2. Assign a category to a merchant only when the name makes it clear. Supermarkets, cash withdrawals, payments to people and unknown names are "Unsure". Ask me one question for each Unsure group.
3. Show the category totals and the file total side by side, so I can see that they match. Show your arithmetic. If you cannot do the sums reliably, say so.
4. Do not say anything is tax deductible. That is for my accountant.

My categories: [list, or "propose a short list"]
My business: [one line]
ROWS:
[paste here]

How to check the result

Check the totals first. The category totals should add up to the total of the file. Add them yourself in a spreadsheet. If they do not match, a row was dropped or counted twice.

Then answer the questions about the Unsure groups. Be specific, for example "that is my accountant's fee" or "that is a personal payment". Ask the assistant to update the table, and check the totals again.

Look at the clear assignments. A merchant that does two things, such as a shop that sells both stationery and food, can be wrong even when the name seems clear.

Keep the final table and your answers. Next month you can paste them in as a starting point.

What good output looks like

This is an invented illustration of the shape. A merchant group reads: "Example Software Ltd, 3 payments, total 36.00, category: Software." An unclear one reads: "J Smith, 2 payments, total 240.00, category: Unsure. Question: who is J Smith and what were the payments for?" A supermarket line is Unsure, too, because it could be office supplies or personal spending.

The summary at the bottom shows each category total and then the file total, with the two matching. If the assistant says they match but you add them up and they differ, trust your sum and ask for the arithmetic again.

When your bookkeeper asks how a line was decided, you can point to your answer to the question. Keep that list. It becomes the rulebook for next month: the same merchant gets the same category without being asked again.

Limits

• It is bookkeeping help and not tax advice. It never says something is deductible. A qualified accountant decides that.
• It does not know your business. Anything it cannot tell from the name becomes a question for you.
• Amount formats vary. Check unusual ones against the file total.
• It does not touch your bank or your accounting software.

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