When do you need to register for VAT?

You must register for VAT if your taxable turnover exceeds £90,000 in a rolling 12-month period (current threshold for 2025/26).

You must register:

• Within 30 days of the end of the month in which you exceeded the threshold

Once registered, you must begin charging VAT from your effective date of registration.

What counts as taxable turnover?

Taxable turnover includes:

• Standard-rated sales (20%)

• Reduced-rated sales (5%)

• Zero-rated sales

It does not include:

• VAT-exempt income (e.g. certain financial services, residential rents)

Should you register voluntarily?

Even if your turnover is below £90,000, it may still be beneficial to register voluntarily.

You should consider voluntary registration if:

• Your customers are VAT registered businesses
• You incur significant VAT on expenses
• You want to appear more established or credible

The key benefit is that you can reclaim VAT on your costs.

However, if your customers are not VAT registered (e.g. general public), registering may make your prices less competitive.

What happens once you are VAT registered?

Once registered, you will need to:

• Charge VAT on your sales
• Submit VAT returns (usually quarterly)
• Keep digital records (Making Tax Digital rules apply)
• Pay any VAT due to HMRC

Most modern accounting software will handle VAT calculations and submissions.

How HMRC monitors VAT registration

HMRC actively identifies businesses that should be VAT registered.

It uses data from:

• Card payment providers
• Wholesalers and suppliers
• Tax returns and third-party data

If HMRC believes your turnover exceeds the threshold, it may send you a letter asking you to:

• Register for VAT, or
• Explain why you are not required to register

What should you do if HMRC contacts you?

If you receive a letter from HMRC:

• Do not ignore it
• Respond promptly
• Seek professional advice

HMRC’s data is not always correct, but failing to respond can lead to:

• VAT assessments
• Penalties
• Interest charges

Penalties for late registration

If you fail to register on time, HMRC can:

• Backdate your VAT registration
• Charge VAT on past sales
• Apply penalties and interest

This can be costly, especially if you cannot recover VAT from customers retrospectively.

Common mistakes to avoid

• Only checking turnover annually instead of on a rolling 12-month basis
• Forgetting to include all taxable income
• Delaying registration after exceeding the threshold
• Registering voluntarily without considering pricing impact

Final thoughts

VAT registration is a key milestone for growing businesses.

While compulsory registration is based on the £90,000 threshold, voluntary registration can also be beneficial in the right circumstances.

The important thing is to monitor your turnover regularly and plan ahead to avoid unexpected VAT liabilities.

Action point:
Review your turnover regularly and consider whether VAT registration — compulsory or voluntary — is the right step for your business.