An invoice from a limited company has to carry your full registered company name, a unique number, the date, your customer's name and address, a description of what you supplied, and what it costs. If you're registered for VAT, several more fields become compulsory, and below £250 you can use a shorter version. Everything beyond that is there to get you paid.

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What an invoice has to contain

Most of what goes on an invoice is set by law rather than by convention. That's also why a correctly worded one protects both sides if a sale is ever disputed, and makes your income straightforward to prove if HMRC asks.

Getting your customers to pay you promptly is fundamental to cash flow management, and the invoice is where that starts.

Here is the baseline for a limited company that isn't registered for VAT, from GOV.UK's invoices: what they must include:

Two of those are worth a moment. The registered name is the one with teeth: the Company, Limited Liability Partnership and Business (Names and Trading Disclosures) Regulations 2015 require a company to disclose its registered name on 'bills of parcels, invoices and other demands for payment, receipts and letters of credit'. Invoices are named in the regulation itself. You can trade under another name, but the registered one has to appear on the document. Failing to do that is an offence by the company and by every officer in default, which is rarely prosecuted and still not a line to be on the wrong side of.

The word 'invoice' is the opposite case. Plenty of guides list it as a legal requirement, and it isn't one. It is simply good practice, because it tells your customer's accounts team what the document is for and separates it from a quote, a receipt, or a bill. Use it anyway.

One more rule applies if you list your directors: name one and you must name all of them. Most companies leave directors off the invoice entirely, which is the simpler option.

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Your company number and registered office: where they're actually required

Almost every invoicing guide tells you your company registration number and your registered office address are compulsory on an invoice. They aren't, and it's worth knowing why, because the rule is more specific than it looks.

The 2015 Regulations split the obligation in two. Regulation 24 covers the registered name, and it lists invoices explicitly. Regulation 25 covers the further particulars – the part of the UK your company is registered in, the registered number, and the address of the registered office – and it applies to business letters, order forms, and websites. Invoices are not in that list. GOV.UK's own invoicing page agrees: for a limited company it asks for the full company name as it appears on the certificate of incorporation, and nothing else.

So the honest answer is that your number and registered office are required somewhere, just not here. Include them anyway. They cost one line, they help a customer verify you on Companies House before paying, and a company that puts its number on its paperwork looks like one that keeps records. The point is to know which fields you can't leave off and which you're choosing to add.

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What changes when you're registered for VAT

Once you're registered, your invoices stop being general business documents and become VAT invoices, with a list of required contents set out in regulation 14 of the Value Added Tax Regulations 1995. HMRC repeats it in section 16.3.1 of the VAT guide (VAT Notice 700). Everything above still applies, plus the following:

The regulation is the authority, and two of its requirements get skipped so often that they're worth saying out loud. The unit price applies to anything countable – an hourly rate, a price per item, a standard service charge. If a job can't be broken into countable parts, the total excluding VAT is the unit price. HMRC also allows you to leave it off where a unit price isn't normally given in your sector and your customer hasn't asked for one.

If an invoice mixes standard-rated work with anything zero-rated or exempt, you have to show clearly that no VAT is payable on those items and give them their own separate total. Putting everything in one line and applying an average rate isn't allowed.

Construction companies have one extra line to get right. Where the domestic reverse charge applies, the invoice has to carry the reference 'reverse charge', note that the customer is the one accounting for the VAT, and state the VAT due – or just the rate – without including it in the amount you're charging. HMRC accepts 'VAT Act 1994 Section 55A applies', 'S55A VATA 94 applies', or 'Customer to pay the VAT to HMRC' as wording that meets the requirement, in its VAT reverse charge technical guide. The VAT you charge then flows through to your VAT return in the usual way.

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Invoices for £250 or less: the simplified version

For small sales you don't need the full document. Where the consideration doesn't exceed £250, regulation 16A lets a VAT-registered business issue a simplified invoice carrying only your name, address, and VAT number, the time of supply, a description of what you supplied, the total payable including VAT, and the VAT rate for each rate charged.

Look at what that drops: your customer's name and address, the invoice number, the date of issue, and the split between net and VAT. It's a genuinely shorter document.

There's a condition the guides almost always leave out, and HMRC states it plainly in section 16.6.1 of the VAT guide: your customer has to agree. A business customer who needs the net figure and your invoice number for their own records is entitled to a full VAT invoice, and if you make retail sales you have to give one when a VAT-registered customer asks. So treat the simplified invoice as the option for low-value sales where nobody has asked for more, not as your default below £250.

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Invoicing when you're not registered for VAT

Below the registration threshold, the rule is short: you must not show VAT on your invoice. Not as a line, not folded into the total, and not as 'VAT to follow'. You can't charge it until you're registered.

That matters more than it sounds, because there's a penalty attached. Issuing an invoice showing an amount as VAT, or as including VAT, when you aren't authorised to is penalised under paragraph 2 of Schedule 41 to the Finance Act 2008.

If you want to check that for yourself, use the Finance Act rather than the reference you'll usually be given. Most sources cite section 67 of the VAT Act 1994, which was repealed with effect from 1 April 2010.

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Which date to put on the invoice

There are two dates on an invoice and they do different jobs. The supply date records when the work happened. The invoice date records when you raised the document. For a VAT-registered company the gap between them decides which VAT period the sale falls into, and that's the part worth understanding.

Your basic tax point is the date you sent the goods or the customer collected them, or for services, the date the work was finished. Invoice before that date, or take payment first, and the tax point moves to whichever came first.

Then there's the rule that does the real work. Issue your VAT invoice within 14 days of the basic tax point and the invoice date becomes the tax point, which is what lets most companies invoice in arrears and account for the VAT in the period they billed. Issue it more than 14 days late without HMRC's approval and the VAT falls due at the basic tax point instead – so a job finished in March and invoiced in April lands in the earlier quarter, and the VAT is payable sooner than your own records suggest. HMRC sets this out in section 14.2.2 of the VAT guide, and will extend the 14 days if you ask and have a reason, such as invoicing monthly in arrears.

A quote or a proforma invoice creates no tax point at all, which is exactly why it's useful for agreeing a price before you commit to a VAT position.

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The fields that make an invoice harder to dispute

Everything above makes an invoice correct. What makes it get paid is a different, shorter list, and it's all about removing reasons to put your invoice to one side.

Start with the reference your customer asked for. If they raised a purchase order, their accounts payable system will try to match your invoice to it, and an invoice with no PO number often sits in a queue until someone has time to work out which budget it belongs to. The same goes for a named contact: address it to the person who approved the work, not to 'Accounts'.

Then the payment terms and the due date, as an actual date rather than 'net 30'. This is where leaving a field blank costs you something real. If you and your customer never agree a payment day, the law supplies one: under the Late Payment of Commercial Debts (Interest) Act 1998 the payment is late 30 days after the later of delivering the goods or finishing the work, and the customer receiving notice of the amount – in practice, the day your invoice arrives. GOV.UK puts it the same way on late commercial payments: interest and debt recovery. An agreed date is usually expected to be within 60 days for business transactions, and longer terms have to be fair to both sides. Writing the date on the invoice is how you make your terms yours rather than the default, and agreeing payment terms up front is what gives you something to write.

Last, make paying easy. Put your bank details on the invoice itself rather than in the covering email, where they get lost in a thread, and give your customer a way to pay that doesn't involve setting one up from scratch. iwocaPay is one option: your customer can pay straight away or spread it over 30 days, 3 months, or 12 months, and you're paid upfront either way.

If the due date passes anyway, chasing an unpaid invoice is a different job with its own rules.

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How to send it

Email is fine, and so is a messaging app for a small job. Nothing in the rules says an invoice has to be posted or signed. Send it as a PDF rather than an editable document, so the figures can't be changed after it leaves you and the layout survives the journey.

Send it to whoever actually processes payments, copying the person who commissioned the work, and keep your copy. VAT records, including copies of the invoices you issue, have to be kept for six years. Until your customer pays, the invoice sits on your books as an open invoice.

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Invoice FAQs

Does my company number have to be on my invoice?

No. Your company number, the part of the UK you're registered in, and your registered office address are required on your business letters, order forms, and website, not on your invoices. What does have to be on the invoice is your full registered company name. Adding the number anyway is sensible, and it isn't compulsory.

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Can I charge VAT if my VAT registration hasn't come through yet?

Not as VAT. Until you have a registration number you can't show VAT on an invoice, and there's a penalty for doing it.

The usual approach while you wait is to raise your prices to cover the VAT you'll owe, explain why to your customers, and then reissue proper VAT invoices once your number arrives so they can reclaim it.

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What should I do if I've already sent an invoice with a mistake on it?

Don't correct it and resend it under the same number. An invoice number has to uniquely identify one document, so overwriting one breaks the audit trail for both you and your customer. Issue a credit note against the original invoice, then raise a fresh invoice with the right figures and the next number in your sequence.

Everything above is general information about the rules rather than tax advice, and your own circumstances may change the answer. Every figure and requirement on this page was checked against legislation.gov.uk and GOV.UK on 15 October 2026.