HMRC Invoice Requirements: VAT Invoices, Reverse Charge, and MTD

HMRC invoice requirements depend on whether your business is registered for VAT and on the value and nature of the sale. Every invoice needs a basic set of identifying details; a VAT-registered business must add several more fields; and certain transactions — small retail sales, reverse charge supplies, self-billing arrangements — follow their own rules on top.

The Baseline Fields on Any Invoice

Whether or not you are VAT-registered, an invoice should identify both parties and document the sale clearly enough to stand up in your records. That means:

A unique sequential invoice number drawn from a continuous series with no gaps.
The date of issue.
Your business name (or your full name if you trade as a sole trader) and address.
The customer’s name and address.
A description of the goods or services supplied.
The total amount payable.

Limited companies and LLPs must also show their registered company name. This obligation sits in the Companies Act 2006 and covers business correspondence generally, not just invoices.

Full VAT Invoice: What HMRC Requires

Once you are VAT-registered, HMRC treats the following fields as mandatory under the VAT Regulations 1995. A missing field can block your customer from recovering the VAT they paid you, so the list matters:

Your VAT registration number (the nine-digit number on your VAT certificate).
The tax point — the date the supply took place, which is not always the invoice date.
The unit price of each item or service before VAT.
The quantity of goods or extent of services for each line.
The VAT rate for each item (standard 20%, reduced 5%, or zero).
The total excluding VAT.
The total VAT charged, expressed in sterling.
The rate of any cash discount offered.

Zero-rated and exempt items should be flagged clearly so the VAT calculation on the invoice is transparent.¹ The current rate schedule is published by HMRC.²

The tax point deserves a note of its own because it drives which VAT return the supply belongs to. The basic tax point for goods is the date they are removed or made available; for services, the date the work is completed. If you issue an invoice or receive payment before that basic point, the earlier date becomes the actual tax point. If you invoice within 14 days after the basic point, the invoice date can be used instead. A deposit received before delivery triggers a tax point for the amount received.

Foreign Currency Invoices

You can invoice in any currency, but where UK VAT applies, the invoice must also show the total net value at each VAT rate and the VAT itself at each rate in sterling. HMRC accepts two standard conversion methods: the UK market selling rate at the time of supply (rates published in national newspapers count) or the period rate of exchange HMRC publishes. Anything else needs HMRC’s prior approval, and forward rates are not accepted.³

Simplified and Modified VAT Invoices

For retail supplies of £250 or less including VAT, you can issue a simplified (less detailed) invoice.⁴ A simplified invoice drops the customer’s name and address and the per-item breakdowns. It still needs:

Your name, address, and VAT registration number.
The date.
A description of the goods or services.
The VAT rate applied.
The gross total including VAT.

Above £250 you must issue either a full VAT invoice or a modified VAT invoice. The modified version shows VAT-inclusive values rather than VAT-exclusive values for each line and is common in retail settings where till receipts already carry tax-inclusive prices.⁵ Your customer can only reclaim input VAT if they hold an invoice that meets at least the requirements for the correct type given the transaction value.

One boundary worth stating: a pro-forma invoice is not a valid VAT document. If you send one to confirm pricing or request advance payment, you still have to follow it with a proper VAT invoice once the supply happens; your customer cannot reclaim VAT on the pro-forma.⁶

Reverse Charge Invoices

For supplies covered by the domestic reverse charge — most visibly in construction — the customer accounts for VAT rather than the supplier. Your invoice must indicate this. HMRC accepts several forms of wording, including “reverse charge,” “Customer to pay the VAT to HMRC,” or a reference to VAT Act 1994 Section 55A.⁷

The invoice should show the VAT amount due while making clear the customer is the one paying it. You do not charge VAT in the normal way; the customer accounts for it on their own return. Missing this annotation is one of the most common errors HMRC finds in reverse charge audits.

Self-Billing

Under a self-billing arrangement, the buyer creates the invoice on behalf of the seller. HMRC permits this only where both parties have a written agreement covering it, with a start date, an expiry date, and a clause requiring the supplier to notify the buyer of any change to or cessation of their VAT registration. Every self-billed invoice must be clearly marked “SELF-BILLING,” and HMRC treats that wording as having the force of law.⁸

The document itself must carry the same details as a full VAT invoice, including the supplier’s name, address, and VAT registration number. While the agreement is in force the supplier must not issue their own sales invoices for the covered transactions, and you cannot self-bill a supplier who is not VAT-registered or whose registration has been cancelled.⁸

Electronic Invoices

HMRC does not mandate a specific format or electronic signature for digital invoices. An e-invoice is valid where three conditions are met: the supplier’s identity can be verified (authenticity of origin), the content has not been altered (integrity), and the invoice can be read easily (legibility). The customer must also agree to receive invoices electronically.⁹

In practice, you need internal controls that hold those three conditions across the invoice’s life. HMRC’s guidance gives examples: system controls that prevent changes to a sales order after invoicing, procedural controls requiring a purchase order before an invoice is processed, and authorisation controls separating who maintains supplier data from who enters invoices. A recovery plan for system failures and an audit trail linking invoicing to accounting software are also expected.⁹

When to Issue and How Long to Keep Records

VAT Regulation 13 requires a VAT invoice to be provided within 30 days of the tax point.¹⁰ Missing that window does not void the invoice, but it can delay your customer’s input tax reclaim and draw attention on a compliance visit.

VAT records must be kept for at least six years. HMRC can grant a shorter retention on application, but the six-year default is the safe planning assumption.¹¹ Self-employed individuals filing Self Assessment have a separate rule: records must be kept for at least five years after the 31 January submission deadline of the relevant tax year.¹²

Records can be paper or digital as long as they stay legible and accessible for inspection. Where you store invoices electronically, the storage rules in VAT Notice 700/63 apply: authenticity and integrity must be guaranteed throughout retention, and you must be able to reproduce the invoice data as it appeared when originally sent.⁹

Inadequate records carry a penalty of up to £3,000 per failure. That is the maximum, and HMRC can set the figure lower depending on the circumstances. The bigger risk is often that, absent records, HMRC estimates your tax liability during a compliance check.¹³

Fixing Mistakes on an Invoice

Where the price or VAT charged needs to decrease after issue — for a return, a discount, or a billing error — you issue a credit note. HMRC requires credit notes to be issued within 14 days of the decrease in consideration.¹⁴ A valid credit note references the original invoice, explains the reason for the adjustment, and shows the corrected amounts including revised VAT.

If the error has already fed into a submitted VAT return, you can correct it on your next return where the net value of errors is £10,000 or less, or between £10,000 and £50,000 and under 1% of your total sales for the period. Errors above those thresholds, and any deliberate errors, must be disclosed to HMRC separately.¹⁵

You can correct errors going back four years from the end of the accounting period in which they occurred. Deliberate inaccuracies fall under a 20-year time limit.¹⁶

Making Tax Digital and Invoice Records

Making Tax Digital for VAT has applied to all VAT-registered businesses since 2022. You must keep specified records digitally using functional compatible software and submit returns through that software.

For each supply you make, the digital record must include the tax point, the net value excluding VAT, and the VAT rate charged. For each supply you receive, it must include the tax point, the value, and the input tax you intend to claim. Your software must also hold summary data supporting each return, including total output tax and total claimable input tax split by rate.¹⁷

Where more than one piece of software is used — say, a spreadsheet feeding accounting software — the data must move between them through digital links rather than manual re-keying. Spreadsheet users need bridging software to reach HMRC’s systems, and the spreadsheet and bridging software together count as functional compatible software. A carve-out applies to petty cash: individual purchases under £50 including VAT do not need to be recorded individually, provided the total per entry does not exceed £500 including VAT.¹⁷

1
GOV.UK. VAT Traders’ Records Manual – VATREC5010
2
GOV.UK. VAT Rates
3
GOV.UK. Transactions in Foreign Currencies and VAT
4
GOV.UK. VAT Traders’ Records Manual – VATREC16042
5
GOV.UK. Record Keeping (VAT Notice 700/21)
6
GOV.UK. VAT Traders’ Records Manual – VATREC9020
7
GOV.UK. VAT Domestic Reverse Charge Technical Guide
8
GOV.UK. Self-Billing (VAT Notice 700/62)
9
GOV.UK. Electronic Invoicing (VAT Notice 700/63)
10
GOV.UK. VAT Traders’ Records Manual – VATREC6010
11
GOV.UK. Compliance Handbook – CH15300
12
GOV.UK. Business Records if You’re Self-Employed – How Long to Keep Your Records
13
GOV.UK. Enquiry Manual – EM4650
14
GOV.UK. VAT Traders’ Records Manual – VATREC13040
15
GOV.UK. Sending a VAT Return – Correct Errors in Your VAT Return
16
GOV.UK. VAT Assessments and Error Correction – VAEC7410
17
GOV.UK. VAT Notice 700/22 – Making Tax Digital for VAT