What Must a UK Invoice Include? The 2026 Checklist
The legal minimum for a UK invoice, what changes if you're a limited company or VAT registered, and the handful of mistakes that get invoices bounced back unpaid.
The short answer
Every UK invoice needs these, without exception:
• The word "Invoice" somewhere obvious, so it isn't mistaken for a quote or a statement
• A unique invoice number, following a sequence with no unexplained gaps
• Your business name and address
• Your customer's name and address
• A clear description of the goods or services supplied
• The date the work was supplied (the supply date, sometimes called the tax point)
• The invoice date, which may differ from the supply date
• The amount owed, and how it breaks down
• Payment terms, meaning when you expect to be paid
That's the baseline for a sole trader. Two things change it: being a limited company, and being VAT registered.
If you're a limited company
You must show the registered company name exactly as it appears at Companies House. "Smith Electrical" won't do if you're registered as "Smith Electrical Services Ltd". You also need the registered office address and the company registration number.
There's one rule that catches people out: if you name any director on the invoice, you must name all of them. Most companies avoid this by naming none.
If you're VAT registered
A valid VAT invoice needs everything above, plus:
• Your VAT registration number
• The tax point (the date of supply for VAT purposes)
• The VAT rate applied to each line
• The total excluding VAT
• The total VAT charged
• The total including VAT
Your customer needs all of that to reclaim the VAT. Leave any of it off and a business customer's bookkeeper will send it straight back, which costs you a fortnight.
If you're not VAT registered, you must not show a VAT line at all, and you must not show a VAT number you don't have. Implying you charge VAT when you aren't registered is a serious problem, not a technicality.
The tax point trips people up
The invoice date and the supply date aren't always the same thing. If you finished the job on the 28th and invoiced on the 3rd of the next month, those are two different dates and both belong on the invoice.
For VAT purposes the tax point is normally the earlier of: the date you supplied the work, the date you issued the VAT invoice, or the date you received payment. It determines which VAT period the sale falls into, which matters if you're invoicing near a quarter end.
What about CIS?
If you're a subcontractor in construction, your invoice also needs to make the labour and materials split obvious, because the contractor deducts CIS from the labour element only, before VAT.
Show labour on its own lines, materials on theirs, then the gross total, the deduction, and the net payable. A contractor who has to work your split out for themselves will either ring you or pay you late. We've covered the calculation in detail in CIS deductions on invoices, explained.
Five mistakes that get invoices sent back
Reusing an invoice number. Numbers must be unique. Duplicates are the fastest way to turn a routine HMRC enquiry into a longer one, and they confuse your customer's accounts payable system into treating the second one as a duplicate to ignore.
Gaps in the sequence you can't explain. If you void an invoice, keep the number and mark it void. Don't quietly skip it.
Vague descriptions. "Electrical work — £850" tells a customer nothing and gives them an easy reason to query it. "Replace consumer unit, 10-way dual RCD, including certificate" is much harder to argue with.
No payment terms. If you don't state terms, the default under the Late Payment of Commercial Debts legislation is 30 days for business customers. If you wanted 14, you had to say so.
Missing bank details. Obvious, and still the single most common reason an invoice sits unpaid for a week. Account name, sort code, account number, and the invoice number as the reference.
Do I have to send a paper invoice?
No. A PDF emailed to the customer is a perfectly valid invoice. You need to keep a copy for six years for HMRC, which is far easier digitally than in a folder in the van.
A working checklist
Before you send, check:
• [ ] It says "Invoice"
• [ ] Unique number, next in sequence
• [ ] Your name, trading name and address
• [ ] Customer's name and address
• [ ] Description specific enough to defend
• [ ] Supply date and invoice date
• [ ] Labour and materials split, if CIS applies
• [ ] VAT number, rate and totals, if registered
• [ ] Total owed and payment terms
• [ ] Bank details and a payment reference
Getting it right without the effort
If you'd rather not build that layout from scratch every time, our free invoice generator lays all of it out for you and downloads a print-ready PDF. It handles VAT inclusive or exclusive pricing, CIS deductions and the construction reverse charge, and there's no signup.
There are versions tuned for sole traders, VAT-registered businesses and CIS subcontractors.
This article is general guidance, not tax advice. If your situation is unusual, check with your accountant or HMRC.
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