VAT for Small Business / Lesson 6 of 8
What a valid VAT invoice needs
One missing field and your customer cannot reclaim. They will notice.
The short answer
- ✓ Missing any required field makes the invoice invalid for your customer's reclaim
- ✓ Invoice numbers must be unique and sequential with no gaps
- ✓ Simplified invoices are allowed for small retail sales
- ✓ You cannot charge VAT until your registration number arrives
The required fields
A VAT invoice must show all of these. Miss one and it is not a valid VAT invoice, which means your customer cannot use it to reclaim.
A unique sequential invoice number
Your business name and address
Your VAT registration number
The invoice date
The tax point, if different from the invoice date
Customer name and address
Description of the goods or services
Quantity, unit price and rate of VAT for each item
Total excluding VAT
Total VAT charged
Total including VATSequential numbering is a rule, not a convention
Invoice numbers must be unique and sequential with no gaps. If you void an invoice, keep the number in the sequence and record it as cancelled rather than reusing it or leaving a hole. Gaps are one of the first things looked at in a VAT inspection.
Simplified invoices
For retail sales up to a modest value you can issue a simplified invoice with much less on it: your name, address and VAT number, the date, a description, the VAT rate, and the total including VAT. No customer details required.
The tax point
The tax point decides which VAT return a sale belongs in. Normally it is the invoice date, but there are exceptions worth knowing.
| Situation | Tax point |
|---|---|
| Normal invoice | Invoice date |
| Payment received before invoicing | Date of payment |
| Goods supplied and invoiced more than 14 days later | Date of supply |
| Deposit taken | Date the deposit is received |
The bit HMRC does not spell out
You must not charge VAT before your registration number arrives. Registration can take weeks, and you may already be liable from an earlier effective date, which leaves an awkward gap.
The accepted approach is to raise invoices for the VAT-inclusive amount without showing VAT or claiming to charge it, then reissue proper VAT invoices once your number comes through. Telling customers in advance avoids an unpleasant surprise. What you must not do is show a VAT number you do not yet have.
Common mistakes
- Leaving gaps in the invoice sequence. An early inspection focus.
- Omitting the VAT number. Invalidates the whole invoice.
- Ignoring the tax point on deposits. VAT is due when the deposit arrives.
- Charging VAT before your number arrives. Not permitted.
Try it on your own numbers
This is the same calculator as the full tool page, using 2026/27 rates.
Check your VAT invoice
Pick the invoice type, then tick what your invoice includes. A valid invoice is what HMRC needs to let you reclaim the input VAT.
Enter the figures printed on the invoice. We check the VAT line actually equals net × rate and that net + VAT = gross.
Completeness
/
Good to reclaim
This invoice has every element of a valid VAT invoice and can support an input-VAT reclaim.
Still missing
Figure cross-check
- VAT should be (%)
- Gross should be
- Figures match
Guidance only. Always keep the original invoice for your VAT records.
Saved checks
| Type | Result | Complete | Figures | |
|---|---|---|---|---|
Key takeaways
- ✓ Missing any required field makes the invoice invalid for your customer's reclaim
- ✓ Invoice numbers must be unique and sequential with no gaps
- ✓ Simplified invoices are allowed for small retail sales
- ✓ You cannot charge VAT until your registration number arrives
Check you have got it
3 quick questions. No score is kept, and you can change your mind.
1. You omit your VAT number from an invoice. What is the consequence?
2. You take a deposit in March and deliver in June. When is the tax point?
3. Your registration is being processed and no VAT number has arrived. What should you do?
Sources
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