Suprisingly, the UK are not digitally ready:
Holidaymakers may have to use paper Covid certificates to prove they have been vaccinated when the foreign travel ban is lifted from May 17, it emerged on Tuesday.
Downing Street admitted that the NHS app may not be ready for use as a vaccine passport in time and the Government is preparing for "another approach" for holidaymakers travelling abroad in the interim.
At least 20 countries have already indicated that they will accept vaccination certificates as an alternative to PCR tests for holidaymakers to prove their Covid status. Only Greece, however, has so far explicitly said that it will take paper certificates, despite concerns that they are more easily forged.
Rita Marques, Portugal's tourism minister, has said her country would accept only a digital pass because of the risk of fakes. Spain, due to trial its app at more than 40 airports, has said it is in talks with the UK Government over the need for a "mutually recognisable" app.
A senior industry source involved in discussions on the technology said: "I suspect they will take whatever evidence we have in the short term, whether it is another private app solution, a paper certificate, a letter from your GP or a negative PCR test."