Some cheap tests that have been sold through British Airways and TUI may not have been authorised for use without clinical supervision.
Tui announced earlier this year that it was partnering with a Covid test provider called Chronomics to provide packages from just £20.
British Airways has a similar deal with another company, Qured, which provides tests for just £33 that you can take in your suitcase and use before returning to UK.
Travellers took the Qured tests while being supervised via videolink. The tests provided by Tui and Chronomics did not include supervision.
The regulator the Medicines and Healthcare products Regulatory Agency (MHRA) has said: 'We are reviewing lateral flow testing kits sold by a number providers to establish whether the test kits are CE marked and being marketed and used in accordance with that CE mark. Tests which are CE marked for professional use should not be used for self-testing via a video link.'
Unlike many other countries, the UK allows people to enter the country using lateral flow or rapid antigen tests. These are cheaper and quicker than the PCR tests insisted on by most destinations.
However, very few tests of these tests have been authorised for self-use. Until fairly recently the only test that had been approved for self-use was the one distributed through the NHS.
Tests that are approved for self-use should have a four-digit number after the official CE mark but many tests were sold without this authorisation.
Qured provides supervision over video for the tests they sold but this is not sufficient for those that are approved for professional use only.
The MHRA says: 'The supervision may not be via video link or other telehealth approach unless the test being used is regulated as a self-test.'
Both Chronomics and Qured told us that their tests are now authorised for self-use.
Qured told us that it is no longer selling tests which were only authorised for professional use. It said:
'We are now distributing new kits which have a CE mark for self-testing. We no longer sell the professional use kits, however the MHRA has confirmed these can continue to be processed for anyone who already has one.'
'The tests for sale on our website are fully approved for use by individuals under video supervision. All of our tests can continue to be processed and customers will be able to use the results to return from overseas.'
Chronomics told us: u201cThe tests we have sourced for Test to Return are CE Marked and authorised for self-test by a lay person in Europe and in the UK. In addition, this test fully complies with the UK Government's requirements for Test to Return and does not require physician or video oversight.'
All professional-use tests and self-tests should have a CE mark, which the manufacturer puts on it to confirm they've met the regulator's requirements.
Self-tests have to go through additional checks and be officially approved. If this is the case they will have a four-digit number next to the CE mark on the packaging. Both Qured and Chronomics tests should now have the number 0123 after the CE mark. This confirms they've been approved by a German organisation called TuV Sud.
If you've bought a self-test that doesn't have this number after the CE mark on the packaging then let us know at firstname.lastname@example.org.
It's possible that some people have already bought tests that were not approved by the regulator.
The Department of Health and Social Care (DHSC) says: 'Self-administered pre-departure tests are valid, so long as they have a valid CE mark AND a 4-digit identifier number next to the CE mark symbol on the packaging.'
There is a question mark more generally over how Border Force is able to check whether tests have been authorised, particularly if they are bought overseas.
British Airways told us: 'We work with a range of third party testing providers to ensure that our customers can access safe, convenient and affordable testing options. This third party testing provider has confirmed that they are following the applicable guidance.'
Tui told us: 'Our testing partner Chronomics is Government-authorised and they have been in contact with the MHRA throughout the process, working closely with them around all COVID testing products.
For the Test to Return test, Chronomics have worked closely with a CE marked rapid antigen test manufacturer to ensure all steps introduced for the delivery of travel testing fall inside the scope of that CE mark.
We're excited to be taking holiday makers away again, and will continue to work closely with the Government and our suppliers to ensure the testing we offer continues to meet the requirements for safe travel.'