More than 8,700 chain stores have close so far this year, far outpacing the number of new openings.
The overall number of shops has fallen by 5,251, with fashion stores by far the worst affected, according to the Local Data Company.
It said the number of new store openings for the first half of 2021, at 3,500, was the lowest since it started gathering data in 2016.
The bulk of the closures have been on high streets, with retail parks suffering the fewest closures.
