Invoicing guides

An invoice is the paper that turns work into money. If it is incomplete the customer pays late and your accountant sends it back. If it is clear you get paid sooner. The notes below are the three things to hold in your head. They were read on gov.uk on 24 October 2026 and the links are at the foot.

Three things to know before you write one

First, a UK invoice needs a fixed set of fields. Your business name and address, a unique invoice number, the invoice date and the due date, the client name and address, the job address where the work was done, the job title, each line with description and quantity and unit price and amount, subtotal, VAT rate and VAT amount where you charge VAT, total, amount paid to date and balance, your VAT number if you are VAT registered, payment terms and how to pay, and your bank details with account name and sort code and account number. The app fills most of these from the job so you do not retype them.

Second, VAT and CIS change the bill in different places. VAT sits on the total: subtotal plus VAT equals total. CIS sits after the total as a deduction on labour only and reduces what is payable on that invoice. Materials and VAT are never inside the CIS deduction. The app adds the VAT row only when you have a VAT number in Settings and the VAT is above zero, and the CIS block only when CIS is switched on and the customer is a CIS contractor.

Third, every invoice needs a payment reference the customer cannot get wrong. The app uses the invoice number as the reference and prints it in the bank block as Reference: INV-2041. The customer puts that on the bank transfer and you can match the payment without asking. The same reference rides on every chase for that invoice.

How payment terms work

Set a clear due date. Fourteen days is common on domestic work. Say it on the invoice and in the payment note that sits under the total. The app carries a payment note you set once in Settings under How you get paid. It starts as Payment is due on completion, by bank transfer, before I leave site. Change it to your own words or switch it off. When it is on it sits under the total on every quote and bill so the customer is told when and how before you have to say it out loud.

When the due date passes the invoice becomes late. You can chase it. The law gives a business customer statutory interest at 8 percent above the Bank of England base rate plus a fixed sum, unless you have agreed another rate in writing. Rates were read on gov.uk on 24 October 2026. That rule is for business to business. Interest at the agreed rate replaces it only where you have agreed it.

The four steps of chasing

House style on this site is the same ladder the app uses, in the trader’s own words. It is the same four letters on the template pages and in the app.

One, on the due date, a friendly reminder with the amount still owed and your bank details already in it. Two, at about seven days overdue, a short nudge that names the due date, the amount and the bank details. Three, later, a firmer letter that sets out the balance, adds any interest you are due, and says what will happen if you are not paid. Four, the letter before action that gives a final date, usually 30 days, and says you may start a claim.

The app fills each chase with the amount still owed rather than the original total, and with the bank details and the invoice number so the customer can pay from that one message. The customer’s page for that invoice carries the same link, the bill, and a box to confirm the work was done.

Calculators for invoicing

• Late payment interest calculator: work out statutory interest at 8 percent above base rate and your own fixed rate, and see what is different for a customer who is not a business.
• CIS calculator: check a CIS deduction at 20, 30 or 0 percent on labour only before you raise the bill.
• VAT calculator: check VAT at the three UK rates when you add or remove it from the price.

Templates for invoicing

• Invoice template: a full worked invoice. It shows a VAT breakdown and a CIS block where that applies. It also shows the payment reference and the bank block.
• Statement of account template: what a customer owes across all jobs, dated and signed, useful when the customer wants one summary.
• Late payment letter template: the four steps as letters you can copy, with the letter before action and the small claims note at the end.
• Payment reminder template: the same ladder in message form, one thing per line.
• Job sheet template: what was done, what was found, what was used, what was photographed, and what the customer signed. It backs the invoice when the customer asks what they are paying for.

Each specimen shows numbers that add up and a real looking customer and address marked as an example.

Posts on invoicing

Each post carries a key facts box at the top and sources at the foot. The legal bits name the requirement, not a summary.

• How to chase unpaid invoices: the four letters written out in full with the bank details and the reference in place.
• Late payment interest explained: statutory interest at 8 percent above base, your own fixed rate, and when interest does not apply.
• How to raise a VAT invoice: what a VAT invoice must show and when a simplified invoice can be used.
• Self Assessment for solo traders: what invoices and statements your accountant wants at year end.

Related pages in the app

• Invoices: a bill built from the job, with the invoice number as the payment reference and the balance shown.
• Chasing: the chase in your own words, with the amount still owed and the bank details already in it.
• Payments: deposits and part payments on one job, with the money still owed rather than the total.
• Customer messages: four messages for the four moments, where a blank box sends the app’s own words.

Sources

VAT invoice rules and late payment rules read on gov.uk on 24 October 2026.

Latest from the blog

The newest posts on invoicing sit here with the newest first. Until they are live the list below is planned and will appear as each post is published.

• How to chase unpaid invoices: the four step ladder and the letters you can copy.
• Late payment interest explained: statutory interest at 8 percent above base rate and your own fixed rate.
• How to raise a VAT invoice: the fields a VAT invoice must show and the £250 simplified invoice rule.

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