You must register for VAT if your VAT-taxable turnover went over GBP 90,000 in any rolling 12-month period, or if you expect to pass GBP 90,000 in the next 30 days alone. The threshold is a registration trigger, not a tax-free band: once registered you charge VAT on all your taxable sales.
Registration threshold - GBP 90,000 of VAT-taxable turnover. Cross it and you must register
Deregistration threshold - GBP 88,000. You can cancel your registration if turnover falls below this
Rolling 12-month test (backward) - You must register if turnover went over GBP 90,000 in any...
Next-30-days test (forward) - You must register if you expect turnover to pass GBP 90,000 in the...
Plus 6 more in the full guide

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