Eighty-two Covid travel test providers have been issued a two-strike warning following an internal review into misleading prices.
The testing companies, which feature on the government's list of approved providers for holidaymakers, could be removed from the official website because of excessive rates, the Department of Health today said.
The firms, which make up around 18% of those on the government travel test website, added extra charges at the point of sale, meaning customers were told to pay more than initially advertised at the last minute.
The prices will now be updated and the companies have been warned that they will be removed if they advertise misleading prices again.
A total of 57 companies that longer exist or do not provide day two and day eight testing will also be removed from the government list on Monday.
We've have a full guide on Covid travel tests and how to avoid over-paying, here.
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.
"57 firms will be removed from the GOV.UK list and a further 82 will be given a 2-strike warning – if they advertise misleading prices ever again, they’re off.
"We are also introducing regular spot checks this week to make sure all private providers follow the rules and meet our high standards of transparency.
"Companies will be removed from the Gov.uk list if they fail to take action within 3 days of strike 1 as part of the new 2-strike policy."
The findings of the review will be shared with the Competition and Markets Authority after it launched an investigation into excessive prices this month.
One Mirror reader, Steve, was told to pay £160 for a day two test alone after arriving in England from South Africa. He paid just £42 for the same test in his departure country.
We've heard from at least a dozen more travellers who say they felt forced into paying excessively high prices for tests on arrival to England, amounting to hundreds of pounds for a family break.
Tests booked for travel with companies not listed on the government website can still be used for travel, providing they meet legal requirements. Some firms, such as Tui, will also offer discounted tests for passengers through their own approved-providers.
Earlier this month it was confirmed that UK holidaymakers will benefit from cheaper travel testing packages going forward.
On August 13, the cost of NHS Test and Trace tests for international arrivals were reduced from £88 to £68 for green or fully vaccinated amber arrivals, and from £170 to £136 for two tests for amber arrivals who are not fully vaccinated.
It came after firms complained that the price of PCR tests are putting families off booking a holiday, with costs reaching as much as £1,000 for a family of four.
The number of PCR tests you need to take before, during and after your holiday is dependent on the travel light system, as well as what part of the UK you live in.
England, Scotland, Wales and Northern Ireland currently have the same green list, while England has an additional green watch list.
It means every traveller from the UK has to take at least one test before they fly back home - this can be a PCR or antigen test - and then get tested again at least once after getting back.
