Bookkeeping
What to send your accountant each month
The short list of records your accountant needs about your sales each month, what a sales register is, and how to stop the back-and-forth of questions.
7 Oct 2026 · 6 min read
It is the week your tax return is due. Your accountant sends a list of questions: which invoice does this bank payment belong to, why is number 0067 missing, was this customer charged tax. You spend an evening looking for answers in old emails. None of the questions was hard. They were only asked a month too late. Sending the right five things every month makes that list disappear.
The five things
| What | Why your accountant needs it |
|---|---|
| Sales register | Every invoice and credit note of the month, with the net amount and the tax apart |
| Payments received | Which invoices were paid, on which date and how |
| What is still unpaid | Each open invoice with its due date, as of the last day of the month |
| Bank statement | So the payments can be checked against the money that arrived |
| Anything unusual | A cancelled invoice, a refund, a customer abroad, a short payment |
This list covers your sales, the money coming in. Your accountant will also want your costs: supplier bills and receipts. Those come from a different place, so keep them as a separate bundle.
What a sales register is
A sales register is a list of every invoice and credit note you issued in a period, one line each. It is the first thing an accountant asks for, because the tax you owe on your sales is worked out from it. A useful one has these columns:
- the document number and its date;
- the customer, and their tax number if they gave one;
- the net amount, before tax;
- the tax rate and the tax amount, in their own columns;
- the total;
- the currency, if you bill in more than one.
Send it as a spreadsheet or CSV file, not as a PDF or a photo. Your accountant will sort it, add it up and load it into their own software, and none of that works on a picture.
Three things that save the most questions
No gaps in the numbers
The first check on any register is that the invoice numbers run in order with none missing. A cancelled invoice should still appear, marked cancelled, with its number. A missing number looks like a hidden sale. See how to number invoices.
Credit notes on their own lines
A credit note lowers your sales and your tax for the period it is issued in. It should be its own line with a minus sign, not a quiet change to the original invoice. See how to fix a wrong invoice with a credit note.
Payments matched to invoices
A bank line that says “TRANSFER 4410” tells your accountant nothing. If every payment is recorded against its invoice before the month closes, the bank statement explains itself. See how to match bank payments to invoices, and why a client paid less for the ones that do not add up.
A ten-minute routine for the first week of the month
- Issue any invoice from last month that is still a draft, or delete it.
- Record every payment that arrived, against its invoice.
- Download the sales register for the month.
- Download the list of what is unpaid as of the last day.
- Send both, with the bank statement, in one message. Add one line for anything unusual.
A monthly habit matters more than a perfect one. Twelve small bundles are easy to check. One box of papers in the last week of the year is not.
What to ask your accountant once
- Do you want the records monthly or quarterly, and by which day?
- Which file type suits your software?
- Do you want sales by invoice date or by payment date? The answer depends on how your tax is worked out.
- How should sales to customers in other countries be shown? See how to bill clients abroad.
The short version
- Each month send the sales register, payments received, what is unpaid, the bank statement and a note on anything unusual.
- A sales register lists every invoice and credit note with net, tax and total in separate columns.
- Send it as a spreadsheet or CSV file.
- Keep the numbers unbroken, credit notes on their own lines and payments matched to invoices.
- Do it in the first week of every month.