A new coronavirus contact-tracing app will be launched across England and Wales on 24 September, the government has announced.
Businesses including pubs, restaurants, hairdressers and cinemas are being urged to ensure they have NHS QR code posters visible for customers to scan using the app and check-in.
Health Secretary Matt Hancock described the launch as "a defining moment".
The first version of the NHS contact-tracing app, intended for the whole of the UK, was trialled on the Isle of Wight in May but later abandoned.
"The launch of the app later this month across England and Wales is a defining moment and will aid our ability to contain the virus at a critical time," said Hancock.
Wales’s health minister, Vaughan Gething, said the app’s launch was “an important part of coronavirus response” and that it was sensible for the app to work across the two countries.
Last month the government launched trials of a second contact-tracing app using technology provided by Google and Apple.
The new app will tell people whether they have been close to someone who has had coronavirus and send out alerts advising them to self-isolate.
The contact-tracing app will also include a raft of other features designed to give users "personal benefits" including a countdown timer for people who are self-isolating and alerts about the local level of the virus.
Scotland launched its own app on Thursday that has already been downloaded nearly 600,000 times.
The Protect Scotland app informs people if they have been in close contact with someone who later tests positive.
Northern Ireland was the first part of the UK to launch a contact-tracing app - StopCOVID NI was officially launched at the end of July.