The High Court has dealt a blow to the claimant in a high-profile privacy claim against social media platform TikTok after refusing an extension of time for service.

In SMO (A Child) v Tiktok Inc & Ors Mr Justice Nicklin said that the ‘inescapable reality’ of why the claimant needed an extension was that she had waited until the last minute to meet key deadlines.

The judge said the claimant had tried to gain a tactical advantage by issuing the claim form before the end of the Brexit transition period, but that had set the clock ticking on the deadline for service. ‘The claimant was perfectly entitled to seek that [Brexit-related] benefit, but it came with an unavoidable downside,’ added the judge. ‘Once the claim form was issued, the period within which it had to be served on the service out defendants began to count down.’

The claim is brought by Anne Longfield, the former children’s commissioner for England, representing all children who have used TikTok. It alleges that six named defendants are responsible for invasions of privacy and misuse of private information.

Nicklin said that, despite the high-profile and unusual nature of the claim, the disputed issue was ‘remarkably prosaic’. The claimant had applied for permission to serve the claim form on defendants domiciled outside England and Wales and for an extension of the period within which to serve defendants, notably a privately held company in Beijing, China.

The claimant had six months to serve the claim form from 30 December 2020. Three months elapsed before the claim was stayed pending the Supreme Court decision in data protection claim Lloyd v Google. Once that was handed down on 10 November, the parties had 28 days before the stay was lifted and the time for serving the claim form against TikTok started counting down again.

Nicklin said the claimant’s solicitors must have realised that, without an extension, it had three months in which to serve all defendants. It was not until January this year that they contacted HMCTS to ask the estimated time to effect service in China – the first time this question had been brought up. The solicitors were told it could take over a year – making the existing deadline impossible to meet – but even then it took another six weeks for the claimant to apply for an extension.

The judge dismissed the applications, concluding: ‘The claimant has simply failed properly to attend to service of the claim form until, as they then understood matters, about a week before the time for doing so was due to expire. In that respect, the claimant is no different from the host of other litigants who have failed properly to prioritise service of a claim form and who have unwisely left matters to the last minute.’

He added that the claimant could still issue a separate claim form against the Chinese defendant.

Following the judge’s ruling, Longfield said the court had recognised this was a serious issue and that the decision gave permission to take the ‘necessary steps’ to serve TikTok’s overseas entities in China, the Cayman Islands and the USA.

James Hain-Cole, counsel at the claimant’s solicitors Scott+Scott, added: ‘Complex cases like this often face delays, particularly with overseas defendants. While we note some of the comments from the judge, we are pleased that we can move forward with this important case.’

In a statement, a TikTok spokeperson said: ‘Privacy and safety are top priorities for TikTok and we have robust policies, processes and technologies in place to help protect all users, and our teenage users in particular. We believe that the claims lack merit and intend to vigorously defend the action.’