In general, non-EU businesses do not need a fiscal representative when registering for VAT purposes in UK. Unlike other EU countries, EU and non-EU companies can register directly for VAT in the UK.
Registering directly means that the legal representative of the company can sign the registration form without any local UK involvement.
Non-EU companies in certain industries like e-commerce may be required to appoint a fiscal representative when registering in the UK. Where appointed, the fiscal representative is jointly and severally liable for the VAT obligations of the company.