The decision has been taken about the app model - which is supposed to help to trace the spread of the virus - despite there being concerns about privacy issues.
A spokeswoman for NHSX, the health service's digital innovation unit, explained: "Engineers have met several core challenges for the app to meet public health needs and support detection of contact events sufficiently well, including when the app is in the background, without excessively affecting battery life."
Professor Christophe Fraser, who is one of the epidemiologists advising NHSX, explained that there are specific advantages to using the model the UK has chosen.
According to the expert, a centralised system ought to provide more insights into the spread of the virus.
He told the BBC: "One of the advantages is that it's easier to audit the system and adapt it more quickly as scientific evidence accumulates.
"The principal aim is to give notifications to people who are most at risk of having got infected, and not to people who are much lower risk. It's probably easier to do that with a centralised system."