You have to register for UK VAT as soon as:
- You are a UK business and have made £85,000 of VATable sales in the last 12 calendar months
- You are a UK business and exceed one of the distance selling thresholds in the last calendar year
- You are a non-UK EU business and exceed the UK distance selling threshold
- You are a non-UK business you intend to sell goods from a warehouse in the UK (including dropshipping)
You have the option of registering voluntarily but this is rarely advantageous for ecommerce sellers. It does happen, however, typically only if one of your suppliers will only deal with VAT registered businesses. For full details review our VAT for ecommerce posts.