United Kingdom, April 29 -- Online traders are warning a US TikTok ban could have a "potentially devastating" impact on British businesses.

They hit out after US President Joe Biden signed into law a bill that gives TikTok's Chinese owner ByteDance nine months to sell its stake in the app or it will be blocked in America - a move TikTok says it will challenge in court.

Isobel Perl, founder of Perl Cosmetics in London, is among the army of web traders worried about the impact of a ban as a quarter of her sales now come from the US.

She told the BBC: "(A US ban) could be potentially devastating to businesses in the UK - TikTok is quite a unique way of reaching customers.

"I mostly use TikTok to drive sales to our website. Of all the soc...