Your invoice is part of the service

You've done the work, the client is happy, and now the only thing standing between you and the money is a document. It's tempting to dash off a quick invoice and hope for the best, but a vague invoice invites questions — and questions delay payment. A clear, professional one tells your client exactly what they owe, why they owe it, and when it needs to land in your account. For sole traders and small limited companies, that's often the difference between being paid within a week and chasing for two months.

The details every UK invoice should include

At a minimum, every invoice you send should carry the following:

• Your business details — the name you trade under, your business address, and a phone number or email address so any query reaches you quickly.
• Company information if you're a limited company — the registered company name, your company number, the registered office address and the place of registration, such as England and Wales.
• VAT information if you're VAT registered — your VAT number, and the invoice clearly marked as a VAT invoice.
• Your client's details — their name, address, and any purchase order or reference number they've asked you to quote.
• A unique invoice number — sequential, and never reused.
• The invoice date, and the date you actually supplied the goods or services — these aren't always the same, particularly on longer projects.
• An itemised description of what you're charging for.
• The total amount due, with any VAT shown separately.
• Your payment terms, a clear due date, and your bank details.

Miss any of these and you hand the client a perfectly reasonable excuse to sit on your invoice while they "check something".

Itemise your charges so nothing needs explaining

"Consultancy services — £1,200" makes a client stop and think. "10 hours of website copywriting at £60 per hour, plus £200 for licensed photography" makes them nod and authorise payment. Break your work into lines that match what you agreed at the outset, and use the same basis of charging throughout — hourly, daily or a fixed project fee.

• Show quantities and rates separately from the totals so the arithmetic is obvious.
• List expenses such as travel, materials or subcontractor costs on their own lines, and attach receipts if the client asked for them.
• Reference the project name, job number or site address so the client can match your invoice to their records.
• If you're VAT registered, show the net amount, the VAT rate, the VAT amount and the gross total.

Small clarity now saves a long email later. If you'd want an explanation for a charge someone sent you, itemise it.

Spell out your payment terms

Never leave a client guessing when money is due. State your terms plainly — "Payment due within 14 days" — and then give the actual date: "Payment due by 30 June 2025." A specific date removes all ambiguity, and it's the single easiest way to speed up your cash flow.

• Seven, 14 or 30 days are all normal. Longer terms are more common with larger organisations, so agree them before you start work.
• Ask new or one-off clients for a deposit, typically 25–50% upfront, with the balance on completion.
• Offer more than one way to pay — bank transfer with the account name, sort code and account number clearly listed, or a card and Direct Debit option if you have one.
• For business-to-business debts, you're entitled to charge statutory interest of 8% above the Bank of England base rate under late payment legislation. Mentioning this politely in your terms encourages prompt payment.
• Double-check your bank details before sending. A wrong digit is a delay you've caused yourself.

Number, send and keep your records straight

Give every invoice a sequential number, such as 2025-041, and store a copy of each one you issue. A consistent template — same layout, same fonts, your logo in the same place — makes you look established and makes your invoices quicker to produce. Send them as a PDF so the formatting can't shift, and note the date you sent it.

Keep your invoicing records for at least six years from the end of the relevant accounting period, as HMRC expects. Whether you track them in a spreadsheet or use bookkeeping software, log each invoice as unpaid, part-paid or settled, and reconcile the total against your bank account each month. That way, nothing slips through the cracks and your year-end filing becomes far less painful.

Follow up politely — and always say thank you

End every invoice with a short, genuine thank you for their business. It costs nothing and it keeps the tone friendly if you do have to chase later. If an invoice is significant, a brief courtesy email a few days before the due date — "Just a reminder this is due Friday, no action needed if it's already scheduled" — works remarkably well.

If the due date passes, follow up within a week with a warm, matter-of-fact message assuming an oversight rather than a refusal. Keep the messages short, factual and increasingly formal if the delay continues. Review your invoice template once a year and update your terms, bank details and branding. A tidy, professional invoice is one of the simplest marketing tools a small business has — and one of the most effective ways to get paid on time.