"VAT registration: when you must, when you should".

VAT registration has two triggers — one everyone knows about, and one that catches people out.

The rolling 12-month test

You must register when your taxable turnover in the last 12 months passes £90,000. The part people miss: it is a rolling twelve months, checked continuously — not your accounting year, not the calendar year. A strong November can tip you over a threshold you thought you'd check "at year end". If you're anywhere near the number, the check needs to happen monthly.

The 30-day forward test

You must also register immediately if you expect taxable turnover to exceed the threshold in the next 30 days alone — a single large contract can do this. This test looks forward, not back, and the registration date is the date you formed the expectation, not the end of the month.

Late registration means HMRC treats you as registered from the date you should have been — you owe the VAT on everything since, whether or not you charged it to customers, plus potential penalties.

What registration actually means

• You charge VAT on your sales (currently 20% standard rate for most services) and pay it to HMRC.
• You reclaim VAT on most business purchases.
• You keep digital records and file quarterly returns through Making Tax Digital software.

Whether registration costs you money depends on your customers. If they're VAT-registered businesses, they reclaim what you charge — your prices are effectively unchanged. If they're the general public, VAT is a real price increase or a real margin cut, and timing the registration matters.

When registering early is smart

You can register voluntarily below the threshold. It's often worth it when:

• Your customers are VAT-registered businesses — they don't care about the VAT, and you get to reclaim VAT on your own costs.
• You're investing heavily up front — equipment, stock, fit-out — and want the VAT back on those purchases.
• You want the scale signal — some businesses prefer suppliers who are VAT-registered.

There are also simplification schemes — flat rate, cash accounting, annual accounting — that suit different shapes of business. Which one (if any) fits is a ten-minute conversation with us.

The habit that prevents all of it

One number, checked monthly: taxable turnover for the trailing twelve months. We track it for clients as part of the bookkeeping, so registration is a decision made in good time — never a letter from HMRC about the past.

Official sources: VAT registration (GOV.UK) · VAT rates (GOV.UK) · VAT schemes (GOV.UK)