Do I need to register for VAT if I only sell to customers outside the UK?

UK VAT registration is generally based on your total VAT-taxable turnover, which can include zero-rated exports and some overseas supplies, so you may still need to register even if all your customers are abroad, depending on exactly what you sell and to whom (goods vs services, business vs consumer). The place-of-supply rules for services in particular can be complex and vary by country and sector. Because getting this wrong can create liabilities in more than one country, it's genuinely worth getting specific advice from an accountant familiar with international VAT before assuming you're outside the UK system.