Clarke Willmott has become the first UK firm to advise its lawyers and staff not to comply with US border staff who request access to their social media accounts and phone contacts lists.

The firm has told lawyers they could be breaking UK data protection regulations and client confidentiality obligations if they comply with the current US border regime.

From 20 December 2016 the online system for visitors to the US from countries which benefit from the visa waiver system, which includes the UK, added a new question that states: “Social Media (optional) please enter information associated with your online presence.”

The form then invites the applicant to fill in details of their social media accounts and user names.

Although revealing data connected to social media accounts is currently voluntary for those travelling to the US, reports following the inauguration of President Donald Trump suggest it could be made compulsory and extended to cover a visitor’s website browsing history.

Clarke Willmott head of technology and IP partner Susan Hall said it was this concern that had prompted the firm to warn its lawyers against complying with the system.

“There is growing concern about how this information might be used or stored. There is also concern about what exactly border officials are looking for,” she said.

“At the moment it is voluntary and we are advising people not to tick the box, but it’s looking like it could become compulsory as more extreme proposals are put forward.

“Handing over your own details to somebody you will also be handing over access to your friends, work colleagues and associates. This gives rise to real data protection concerns.”

Hall continued: “We are setting out revised guidelines for our own lawyers to follow with respect to social media, to ensure people are aware of the issues of data protection and client confidentiality compliance which developments like this cover.”

Further UK law firms are expected to follow suit in their advice to lawyers travelling to the US.