More than 50 companies will be removed from the government’s list of approved COVID-19 testing providers.
The move comes following a review of pricing and service standards from those offering day two and day eight tests for people arriving in the UK from overseas.
The review was announced earlier this month due to concerns that many of the companies – which are on a government list of COVID testing services – lacked full accreditation and were charging too much.
Some 57 companies will be removed from the list as they no longer exist or they do not provide the relevant testing services.
Eighty-two companies – around 18% of those listed as offering day two and day eight tests – were found to be displaying lower prices on GOV.UK than they do on their own websites.
Those companies will be given a final warning this week and face removal from the list if they advertise misleading prices again.
There will also be regular spot checks to make sure prices are accurate, providers are legitimate, and that the company name has not simply been changed to get back on the list.
Health and Social Care Secretary Sajid Javid said: “It is absolutely unacceptable for any private testing company to be taking advantage of holidaymakers and today’s action clamps down on this cowboy behaviour.”
In future, companies will be removed from the government’s list if they do not correct problems within three days of their first warning.
The review was announced by Mr Javid earlier this month after complaints about significant differences in price and service at some of the hundreds of firms offering the tests.
Analysis of the list by the Liberal Democrats at that time showed just 11% of the providers offered tests for under £50 but 24% of the providers were charging more than £200.
One GP clinic was listed as offering the tests for £575 on GOV.UK, although its own website said prices started at £399.
PCR tests, which use a swab to detect coronavirus on the tonsils and inside the nose, typically cost around £75.