Abigail Pringle, chief development officer at Wendy's, told the Financial Times that the group will target 50 new openings in 2022, up from the 10 new outlets originally planned.
The new sites will be a mixture of bricks and mortar restaurants, drive-thru locations and dark kitchens.
According to Pringle, revenues at the restaurants it has opened this year are 'far more' than the chain had expected, at £40,000 a week.
Wendy's, which has tried and failed twice to secure a foothold in the UK in the past, has previously said it intends to become a major player in the country's fast food market with plans to open up to 400 sites.
The group opened the first UK restaurant of its new expansion drive in Reading back in June, and has since followed that with sites in Oxford and London's Stratford.
Last week it opened its fourth restaurant, in Croydon, and has lined up further sites in Brighton, Romford and Camden that are set to open in due course.
It has also established four delivery locations.
During the company’s recent third quarter earnings call, Wendy's chief executive Todd Penegor reported 'extremely strong sales' across its growing UK estate, and said the company is on track to have a total 10 locations open by the end of the year.
“We are extremely excited about the consumer response to our expansion into the UK, which drove better than expected sales in these new restaurants during the third quarter," he said.