VAT registration is one of the most common compliance questions for growing businesses. Get the timing wrong and you face backdated VAT liabilities, penalties, and the administrative burden of filing returns you were not prepared for.
The £90,000 Mandatory Registration Threshold
You must register for VAT if your taxable turnover exceeds £90,000 in any rolling 12-month period. This is not based on your financial year, HMRC applies a continuous rolling test. If at the end of any month you look back over the previous 12 months and your total taxable turnover exceeds £90,000, you must register within 30 days.
You must also register if you expect your taxable turnover to exceed £90,000 in the next 30 days alone (the "future test"). This catches businesses that land a large one-off contract.
Taxable Turnover, Not Profit
The £90,000 threshold is based on your gross taxable turnover, not your profit. For e-commerce sellers, this is your gross sales (before marketplace fees). For construction businesses, it includes the cost of materials billed to clients. Many businesses cross the threshold while their actual profit remains modest.
When Voluntary Registration Makes Sense
You can register for VAT voluntarily at any turnover level. This makes commercial sense when:
You sell to VAT-registered businesses (B2B)
Your customers can reclaim the VAT you charge, so it costs them nothing. Meanwhile, you can reclaim VAT on your own purchases. Not being registered when your competitors are can make you look less established.
You have material input VAT (expenses with VAT)
If you buy stock, materials, or equipment with 20% VAT added, registering lets you reclaim that VAT. Importers, manufacturers, and businesses with heavy capital expenditure often benefit from early registration.
You are approaching the threshold quickly
If you are within £10,000-15,000 of the threshold, registering early avoids the panic of mandatory registration and gives you time to set up your systems properly.
When Registration Hurts: B2C Businesses
If you sell primarily to consumers (B2C) who cannot reclaim VAT, registration effectively increases your prices by 20%, or forces you to absorb the VAT within your existing prices, reducing your margin. For B2C businesses below the threshold with low input VAT, voluntary registration rarely makes sense.
Choosing the Right VAT Scheme
Once registered, you need to choose how you account for VAT. The two main options for small businesses:
| Scheme | How It Works | Best fit |
|---|---|---|
| Standard Scheme | You charge VAT on sales, reclaim VAT on purchases, and pay the difference to HMRC quarterly. | Businesses with material expenses (stock, materials, equipment). |
| Flat Rate Scheme | You pay a fixed percentage of gross turnover to HMRC. Simpler, but you cannot reclaim input VAT (except on capital assets over £2,000). | Service businesses with low material costs (consultants, IT contractors). |
The right choice depends on your expense profile. We actively monitor both schemes for our clients and recommend switching when the numbers justify it. Many consultants default to the Flat Rate Scheme but would save money on the Standard Scheme once their expenses reach a certain level.
Frequently Asked Questions
What happens if I exceed the threshold and don't register?
HMRC will backdate your registration to the date you should have registered. You become liable for VAT on all sales from that date, even though you did not charge VAT to your customers. You cannot retrospectively add VAT to old invoices, so the liability comes directly from your profit. Penalties and interest are added on top.
Can I deregister if my turnover drops?
Yes. You can apply to deregister if your taxable turnover falls below £88,000 (the deregistration threshold, which is lower than the registration threshold). This creates a buffer zone that prevents you from cycling in and out of VAT.
How do I file VAT returns under Making Tax Digital?
All VAT-registered businesses must file digitally through MTD-compatible software. We use Xero, which connects directly to HMRC and files your VAT return digitally with a single click once we have reviewed the figures.
Official HMRC & Government Sources
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HMRC: When to Register for VAT
Official HMRC rules on the £90,000 mandatory threshold, the rolling 12-month test, and the 30-day future test.