26 May 2026 · 7 min read · Bruce Thomas
VAT registration is compulsory once VAT-taxable turnover exceeds the registration threshold on a rolling twelve-month basis, or when you expect to exceed it in the next thirty days alone. The rolling test catches people out — it is not measured against your accounting year.
The compulsory test in practice
At the end of every month, add up the taxable turnover of the previous twelve months. If it has crossed the threshold, you must notify HMRC within thirty days of the end of that month, and registration takes effect from the first day of the following month.
Miss it, and you owe the VAT on sales already invoiced without it. For a business selling to consumers, that comes straight out of margin.
Should you register voluntarily?
- Yes, usually, if your customers are VAT-registered businesses — they reclaim the VAT and you recover input tax on your costs
- Yes, if you have substantial purchases, stock or equipment to reclaim against
- Usually not, if you sell mainly to the public and your competitors are unregistered
- Consider it if registration would be credible with larger customers
Choosing a scheme
Standard accounting reports VAT on invoices raised and received. Cash accounting reports it when money moves, which helps if customers pay slowly — a common situation in construction and contracting.
The flat rate scheme applies a fixed percentage to gross turnover with limited input recovery. Since the limited cost trader rules, it is far less attractive for service businesses with low purchases, and a number of businesses remain on it without checking whether it still helps.
What changes after registration
- Sales invoices must show your VAT number, rate and VAT amount
- Digital records and MTD-compatible filing become mandatory
- Returns are usually quarterly, with payment due about a month and a week after quarter end
- You can reclaim input tax on business purchases, subject to the usual exclusions
- Pre-registration input tax can often be recovered on goods and services bought earlier
Planning for the threshold
If you sell to consumers and are approaching the threshold, model the impact before you get there. Absorbing the VAT means a significant margin reduction; passing it on means a price increase. Neither is comfortable, but both are manageable when planned.
This article is general guidance for business owners in the UK and does not amount to advice for your particular circumstances. Tax rules change and the right answer depends on your figures — please take specific advice before acting.
