When HMRC opens a VAT enquiry, or your accountant asks why a £1,840 payment went to repairs, the question is never whether the document exists. It is whether anyone can find it in under a minute. A naming convention and a filing structure decided once, and followed by everyone who touches the books, is the cheapest control a small business can have.
Name every file the same way
Use a pattern that sorts correctly and answers the obvious questions without opening the file:
YYYY-MM-DD_counterparty_document-number_amount.pdf
| Document | Example file name |
|---|---|
| Purchase invoice | 2026-03-14_acme-supplies_INV-20931_1840.00.pdf |
| Sales invoice | 2026-03-15_brightside-ltd_S-1047_2400.00.pdf |
| Credit note received | 2026-03-20_acme-supplies_CN-311_-120.00.pdf |
| Bank statement | 2026-03_barclays-current-0423_statement.pdf |
| Payroll summary | 2026-03_payroll_month-12_summary.pdf |
The rules behind the pattern:
- Date first, in ISO order (year, month, day) so files sort chronologically in any folder.
- Use the document’s own date, not the date you scanned it. The invoice date drives the VAT period.
- Lower case, hyphens, no spaces or special characters. Names survive email, cloud sync and zip files unchanged.
- Gross amount with two decimals. A negative sign marks credit notes and refunds.
- One document per file. A PDF holding three receipts cannot be linked to three different transactions.
A folder structure that follows the financial year
Organise by financial year first, then by document type. Do not file by month inside every type; the file names already sort by date.
Finance/
FY-2026-27/
01-sales-invoices/
02-purchase-invoices/
03-bank-statements/
04-payroll/
05-vat-returns/
06-contracts-and-agreements/
07-fixed-assets/
08-year-end/
Permanent/
company-documents/
leases-and-loans/
asset-purchase-invoices/
The Permanent folder holds documents that outlive a single year: the certificate of incorporation, articles, leases, loan agreements, and purchase invoices for assets you still own. You will need those long after the year they were bought in, for depreciation, capital allowances and disposals.
Attach, do not just store
If you use accounting software, the strongest filing system is the attachment on the transaction itself. Upload the receipt to the bill or the bank line, and the document travels with the figure into every report. The folder structure above then becomes your backup and your place for documents that are not tied to one transaction, such as contracts and VAT return workings.
Under Making Tax Digital for VAT the digital records you must keep are the transaction data in your software. A scanned or emailed invoice is still your evidence for reclaiming VAT, so make sure the attached image is legible and complete, including the supplier’s VAT number.
Who files what, and when
| Document | Filed by | When |
|---|---|---|
| Expense receipts | The person who spent the money | Same day, through the capture app or shared inbox |
| Supplier invoices | Whoever receives them | Within the week, before approval |
| Sales invoices | Generated by the software | Automatically on issue |
| Bank statements | Bookkeeper | Monthly, after reconciliation |
| VAT return and workings | Bookkeeper | On submission |
A shared receipts inbox (for example receipts@yourcompany.co.uk) that forwards to your document capture tool removes most of the chasing. The receipt management guide covers what staff should send and when.
How long to keep it
Keep the folder for each year for at least as long as the law requires: generally six years from the end of the financial year for a limited company, and longer in some cases. The detail, including VAT and payroll records, is in how long to keep accounting records. When a year falls out of the retention period, delete it deliberately, rather than letting old personal data pile up.
Fixing an existing mess
You do not have to rename years of history. Start the convention from the first day of the current financial year, move older files into one “Before convention” folder per year, and attach documents to transactions only when you touch them for a query. Within a year, everything you actually use will follow the new structure.