Anyone who is active in Europe and sells to the United Kingdom must (at least this year and depending on the outcome of the Brexit negotiations) obtain a UK VAT number if a certain delivery threshold is exceeded. Check out our Blog to stay up-to-date.
For this threshold, the turnover from an EU member state to the UK within one calendar year is decisive.
With a VAT delivery threshold of £70,000 (approx. € 77,000), this means that if, for example, a trader registered in Germany sells to the UK and exceeds a turnover of £70,000 within a calendar year, this triggers a VAT liability and the online trader must register for VAT in the UK (ideally before this threshold is reached) as the registration in Germany is not enough anymore.