HMRC has issued guidance on the tax treatment of certain benefits and expenses provided to employees during the Coronavirus (Covid-19). This guidance was recently updated to include the tax treatment of Coronavirus tests.
Where a Covid-19 test is provided by the government as part of its national testing scheme it is not treated as a benefit in kind for tax purposes. Therefore, healthcare workers and other eligible frontline staff to are tested through this national programme do not incur a benefit in kind.
Where employers offer antigen testing kits to employees which are outside of the national testing scheme (offered directly or from a third party) there is no income tax or Class 1A liability.
Furthermore, there is no tax or national insurance liability if the employee receives the money from their employer to get a test. The guidance on the above and other benefits and expenses provided by the employer can be found here.