Box of 7 SARS-CoV-2 Antigen Rapid Test (self-testing), Flowflex brand, lot A1060005, expiry date 16 May 2023, made by ACON Biotech (Hangzhou) Co., Ltd, 17 May 2021

On 9 April 2021, lateral flow tests became available in the UK for regular asymptomatic COVID-19 testing. Data from the Office of National Statistics has shown that around a third of people who tested positive for COVID-19 in September 2021, for example, reported no symptoms.

Rapid lateral flow tests involve rubbing a long cotton swab inside the nose. The swab is mixed with a buffer solution by the user and added to a device like a pregnancy test. The test kit has an absorbent pad at one end and a reading window at the other. Inside the device is a strip of test paper that changes colour in the presence of COVID-19 proteins (antigens). Results are given in 30 minutes. The UK government recommend their use for people with no symptoms of COVID-19 and to use them twice a week. Until January 2022, government guidelines required that people follow up a positive lateral flow test with a PCR test to confirm their results. A positive lateral flow test still required self-isolation and contact tracing.

Free lateral flow tests for the wider population were no longer available in England from 1 April 2022.