Any one that has received their Covid jab has been given a vaccination card, and the details go on their medical records.
The government is now looking at how to allow people to more easily show their Covid status, as “a temporary measure”.
This could mean a record of whether people have been vaccinated, recently tested negative or have natural immunity after being ill with Covid.
It is hoped this could make it easier to reduce social distancing and allow international travel.
It was expected a clear message would be given on Monday night press conference regarding international travel.
But the Prime Minister said their hopes continues to be set for 17 May, saying more data was needed before a firm decision could be taken.
Mr Johnson said he did not want to see coronavirus re-imported from abroad and urged people to await a report from the Global Travel Taskforce on 12 April.
The UK government said it was working with colleagues in Scotland, Wales and Northern Ireland to agree a “consistent approach”.
The government plans to test how Covid status certificates could help crowds return to large events in England, including theatres, nightclubs, festivals and sports events.
A club night, the FA Cup final and a mass participation run are among events which will be part of a study in April and May.
The trials will also look at how social distancing, ventilation and Covid tests when people arrive could be used.
The PM previously suggested pub-goers could be asked to provide a vaccine certificate, after all adults have been offered their first jab by the end of July.
Vaccines Minister Nadhim Zahawi has rules this out saying on Sky News this morning “Next Monday, you can go to a beer garden and have your beer – there is no requirements for vaccine certification or passports that are being referred to,” Mr Zahawi told Sky News.
“In May, you will be able to go inside the pub and enjoy your drink, and there is no question of a vaccine certification being asked for.”
In a round of interviews he said restaurants would not require them before showing diners to their seats either.