1. A business bank account
One account for the business and nothing personal through it. It is the single biggest time saver: every line on the statement is a business transaction you can match.
2. Numbered invoices
Every sale gets an invoice with a number that follows on from the last one, no gaps. If you are VAT-registered it must meet the tax invoice requirements. A mistake is fixed with a credit note, never by editing the invoice.
3. Every slip, kept
Each cost needs proof: the slip or supplier invoice. A photo is enough for most records; a VAT claim needs a valid tax invoice from the supplier. Possible write-offs are flagged as you log costs, with the section of the Act and the proof to keep.
4. Match to the bank
Once a week, tick off each bank line against an invoice or a cost. What does not match is either a missing record or money you did not expect.
5. Close the month
Look at who owes you (a statement with ageing shows how late each customer is), what you owe suppliers, and payroll if you employ people. If you are VAT-registered, prepare the VAT201 for the period.
6. The year-end
Your accountant needs an income statement, balance sheet and trial balance. If your records are matched all year, this is a download, not a project.