I guess this means it is now mandatory to have a smart phone in the UK?

Also, will they sanitize phones before handing them over to pub staff for verification and then sanitize them when handing them back?

Drinkers must hand their phones to pub staff to prove they have registered on the NHS Test and Trace app when beer gardens open on Monday under a tightening of rules to track Covid in hospitality venues

Source: Exclusive: Pub staff will check drinkers’ phones to prove they have registered with Test and Trace

Coldstreams Skeptic