When do I need to register for VAT?
You need to register for VAT when your VAT taxable turnover goes over the registration threshold. GOV.UK currently states that you must register if your total taxable turnover for the last 12 months goes over £90,000, or if you expect your taxable turnover to go over £90,000 in the next 30 days.
The important point is that this is not based on profit, and it is not based only on your accounting year. A business can make modest profit but still cross the VAT threshold if its taxable sales are high enough.
For many growing businesses, VAT registration is one of the first major compliance milestones. It affects pricing, invoicing, bookkeeping, cash flow, software, and customer communication.
The £90,000 VAT threshold is a rolling test
The VAT threshold is not checked once a year. It is checked on a rolling 12-month basis.
That means you need to look back at the previous 12 months at the end of each month. If your taxable turnover for that period has gone over £90,000, you usually need to register. GOV.UK says you must register within 30 days of the end of the month when you exceeded the threshold, and your effective registration date is the first day of the second month after you went over the threshold.
This catches businesses out because they often monitor turnover by tax year, company year-end, or management accounts period. VAT does not wait for those dates.
For example, a business with a March year-end could cross the VAT threshold in July, even though the year-end accounts are not due for months.
What counts as VAT taxable turnover?
VAT taxable turnover is the total value of everything you sell that is not VAT exempt or outside the scope of VAT. GOV.UK says taxable turnover includes standard-rated goods and services, reduced-rated goods and services, and zero-rated goods and services.
This is where businesses often make a wrong assumption. Zero-rated sales still count towards taxable turnover. Exempt sales do not.
For example, if a business sells only zero-rated goods, those sales may still push it over the VAT registration threshold. GOV.UK also says a business with mostly zero-rated taxable supplies may be able to apply for exemption from registration, but it needs HMRC’s permission.
Merranti’s guide to understanding different VAT rates is a useful cross-reference here because businesses need to understand the difference between standard-rated, reduced-rated, zero-rated, exempt, and outside-the-scope supplies. Merranti notes that the standard VAT rate is 20%, but some goods and services have different VAT treatment.
You may need to register before you actually receive the money
VAT registration is based on taxable turnover and expected turnover, not simply cash in the bank.
GOV.UK says you must register if you expect taxable turnover to exceed £90,000 in the next 30 days. It gives the example of arranging a £100,000 contract and needing to register from the date you realised the threshold would be exceeded, not the date the invoice is eventually paid.
This matters for businesses that win a large contract, have seasonal spikes, or suddenly scale through ecommerce, agency work, building projects, consulting, or subcontracting.
If you know a contract will push you over the threshold, do not wait until the invoice is paid to think about VAT.
What happens while you wait for your VAT number?
GOV.UK says you cannot include VAT on invoices until you receive your VAT registration number. However, from your effective date of registration, you may still need to account for VAT to HMRC. GOV.UK says you can increase prices to account for the VAT you will need to pay, then reissue invoices showing VAT once your VAT number arrives.
This is one reason to speak to an accountant before sending invoices around the threshold point.
If you invoice incorrectly, you may create confusion for customers, undercharge VAT, or reduce your own margin because the VAT cost has to come out of the price you already charged.
Should you register voluntarily?
You can register voluntarily if your turnover is below the VAT threshold. GOV.UK confirms that businesses can choose voluntary VAT registration below £90,000.
Voluntary VAT registration can make sense where:
- most customers are VAT-registered businesses that can reclaim VAT
- the business has significant VATable costs
- the business wants to appear more established
- the business is close to the threshold and wants to avoid a rushed registration later
- the owner wants cleaner VAT systems in place before growth accelerates
But voluntary registration is not always beneficial. It can make your prices look higher to non-VAT-registered customers, add administration, and create cash-flow timing issues.
A café, tradesperson, consultant, ecommerce seller, and B2B agency may all reach different conclusions.
VAT registration affects bookkeeping and software
Once registered, a business has ongoing VAT responsibilities. GOV.UK says VAT-registered businesses must charge VAT at the correct rate, keep records of VAT paid and charged, submit VAT returns, and pay VAT owed to HMRC.
VAT returns are usually submitted every three months. GOV.UK also says there are VAT accounting schemes with separate thresholds, including the Flat Rate Scheme, Cash Accounting Scheme and Annual Accounting Scheme.
For businesses already using cloud bookkeeping, VAT may be manageable if the setup is correct. For businesses still using spreadsheets or manual records, VAT registration can expose weak processes quickly.
Merranti’s Making Tax Digital guide for sole traders explains that VAT-registered businesses may already be under MTD for VAT, meaning VAT records and VAT returns generally need compatible software.
What if you register late?
Late VAT registration can be expensive.
GOV.UK says that if you register late, you must pay VAT on sales made since the date you should have registered. It also says a penalty may apply depending on how much VAT is owed and how late the registration is.
HMRC’s late registration penalty notice states that a penalty may apply where a business fails to notify HMRC at the correct time. The penalty is based on the VAT due from the date the business should have registered to the date HMRC was notified or became aware of the requirement.
That means the risk is not only the penalty itself. The business may also need to fund VAT that was never charged to customers.
VAT deregistration is also possible
If your business later falls below the deregistration threshold, you may be able to cancel VAT registration. GOV.UK currently shows the VAT deregistration threshold as taxable turnover below £88,000.
This can matter if a business loses a contract, changes services, sells part of the trade, or restructures.
However, deregistration has consequences, including possible VAT charges on stock or assets in some cases. It should be reviewed properly rather than treated as a simple admin step.
Practical steps before you register for VAT
Before registering, a business should usually review:
- taxable turnover for the previous 12 months
- expected turnover for the next 30 days
- whether supplies are standard-rated, reduced-rated, zero-rated, exempt, or outside the scope
- customer type: VAT-registered businesses or private consumers
- pricing and whether prices are VAT-inclusive or VAT-exclusive
- bookkeeping software
- invoice templates
- cash-flow impact
- whether a VAT scheme may be suitable
- whether voluntary registration would help or hurt
Merranti’s existing article, When Must I Register for VAT?, already explains the compulsory VAT threshold and the rolling 12-month test. That article would be a natural internal link from this post.
Merranti’s How to Register for VAT in the UK is another useful cross-reference for businesses that have already decided registration is needed. It covers the basic registration process and the information businesses are likely to need.
Speak to Merranti before crossing the VAT threshold
VAT registration is not just a form. It changes how your business prices, invoices, records transactions, and reports to HMRC.
If your turnover is approaching the VAT threshold, or you have just won a contract that may push you over it, speak to Merranti Accounting before issuing invoices or making pricing changes.
Merranti can help review whether registration is required, whether voluntary registration makes sense, how to handle invoices during the registration period, and whether your bookkeeping system is ready for VAT. You can contact Merranti through its contact page, which lists office and contact details for the South East, Brighton, London, Redhill and Whyteleaf offices.
