UK Invoice Generator: VAT, Sole Trader and Late Payment Interest 2026/27

Use this UK invoice generator to build an invoice, check it carries everything GOV.UK asks for as a sole trader, limited company or VAT-registered business, and see the interest and fixed charge a late payer owes you.

What must a UK invoice include?

GOV.UK lists the items every invoice must carry: a unique identification number, your company name, address and contact information, the name and address of the customer, a clear description of what you are charging for, the supply date, the invoice date, the amounts charged, any VAT and the total owed. The checklist in the calculator tests those items. It checks that a field is filled in, so it cannot tell you whether a name or address is correct.

The supply date is the day the goods or service were provided. It can differ from the invoice date, which is why the calculator asks for both.

Sole trader invoice: what to put on it

A sole trader invoice carries your own name and any business name you trade under. GOV.UK adds that if you use a business name, you must also give an address where legal documents can be delivered to you. Pick Sole trader in the calculator and the checklist asks for your name instead of a company name.

Here is a worked example. You invoice 10 hours at £50 and one design item at £120, with no VAT. The invoice total is £620, due 30 days after the invoice date unless you agreed something else. The calculator opens with exactly this invoice, so you can change a line and watch the total move.

You do not need a separate template file. The printable invoice the calculator produces is the template: edit the fields, press the print button and save the result as a PDF from your browser.

Self-employed invoice template: when VAT changes it

For invoicing, self-employed and sole trader mean the same thing. What changes the invoice is VAT registration. You must register once your taxable turnover goes over £90,000 in the last 12 months, or you expect it to go over £90,000 in the next 30 days. You must register before you can start charging VAT.

Once you are registered, the invoice must show your VAT number and display the VAT separately. The standard rate is 20%, the reduced rate is 5% and the zero rate is 0%. GOV.UK says a zero-rated sale still goes on the invoice, at 0%. If your customer is also VAT registered, you must use a VAT invoice, which carries more information than a non-VAT invoice.

For example, the same £620 invoice from a VAT-registered business adds £124 at 20%, so the customer owes £744. Switch VAT registered to Yes in the calculator to see it.

A simplified VAT invoice is allowed when the supply is £250 or less and your customer agrees. It still has to show your name, address and VAT registration number, the time of supply, a description and the VAT rate. This calculator produces the full version only.

How VAT is rounded on the invoice

The calculator rounds the VAT on each line to the nearest penny and adds the lines together. HMRC's VAT Notice 700 allows line-by-line rounding to the nearest penny as long as you do it consistently. The calculator does not use the separate allowance to round the total VAT down, so your accounting software may differ from it by a penny on an invoice with many lines.

How the late payment calculation works

If you did not agree a payment date, GOV.UK says the payment is late 30 days after the customer gets the invoice or after you deliver the service, whichever is later. If you did agree a date, it must usually be within 60 days for business transactions.

Statutory interest between two businesses is 8% plus the Bank of England Bank Rate. The Bank of England held Bank Rate at 3.75% in its decision published on 17 September 2026, so the calculator starts with an annual rate of 11.75%. Bank Rate can change at each decision, and the next is due on 5 November 2026. Change the figure in the calculator if it has moved, and check which date's rate applies to your debt before you send a demand.

You can also charge a fixed sum for recovery costs, once for each payment: £40 for debts up to £999.99, £70 for £1,000 to £9,999.99, and £100 for £10,000 or more. You cannot claim statutory interest if your contract sets a different rate, and GOV.UK says to send a new invoice if you add interest to the money you are owed.

A worked example: on a £1,000 invoice paid 50 days late with a Bank Rate of 0.5%, the interest is £11.64. GOV.UK's own example gives £11.50 because it rounds the daily figure to 23p before multiplying by 50 days. The calculator does not round the daily figure first, so its totals can differ from that method by a few pence.

Practical tips

• Put the payment terms on the invoice and in your contract before the work starts. Without an agreed date the payment is only late 30 days after the customer gets the invoice, so writing the date down avoids arguments about when interest starts.
• Number invoices in an unbroken series. For VAT invoices, HMRC asks for a sequential number that uniquely identifies the document.
• Keep the supply date separate from the invoice date. HMRC asks for the time of supply (the tax point) on a VAT invoice.
• If you invoice through your own limited company, try the UK IR35 calculator to see how the same income looks inside and outside IR35.
• If invoices are your side income, use the UK side-hustle tax calculator to estimate the tax on them, and read trading allowance versus expenses before you file.

FAQ

Do I have to charge VAT on my invoices?

Only if you are VAT registered. GOV.UK says you must register for VAT to start charging it, and registration is required once your taxable turnover goes over £90,000. Some goods and services are exempt, so check yours before you register.

Can I charge interest on a late invoice?

Between businesses, yes. The statutory rate is 8% plus Bank Rate, unless your contract sets a different rate, and you can add the fixed recovery sum. Consumers are outside this calculation.

Does the generator save my invoice?

No. The calculation runs in your browser and the calculator does not store or upload your invoice. Close the page and the details are gone, so print or save the PDF first.

Is the checklist legal advice?

No. It reflects the GOV.UK and HMRC lists as they were read in October 2026, in the sources section below. Check high-stakes tax and legal decisions with official sources or a qualified professional before you act.

Sources and assumptions

Default estimate: sole trader, not VAT registered, 30-day payment terms, Bank Rate 3.75%, 30 days paid late. Invoice contents, VAT rules and late payment rules were read from the pages below in October 2026. Maximum four invoice lines, no discounts, deposits, foreign currency or Construction Industry Scheme deductions.

• GOV.UK, Invoices: what they must include
• GOV.UK, VAT guide (VAT Notice 700), sections 16 and 17.5
• GOV.UK, Charge, reclaim and record VAT
• GOV.UK, VAT rates
• GOV.UK, When to register for VAT
• GOV.UK, Late commercial payments: when a payment becomes late
• GOV.UK, Late commercial payments: charging interest
• GOV.UK, Late commercial payments: debt recovery costs
• Bank of England, Bank Rate (checked October 2026)