Medical professionals at Private Harley Street Clinic said there had been a 500% increase in its testing service, with both in-home and in-office testing popular options.
More employers are looking to provide COVID-19 tests as they prepare for a return to normal working practices.
Companies are using both antigen tests, which find out if employees have currently got COVID-19, and antibody testing for those who have already had the virus but went undiagnosed.
Dr. Mark Ali, medical director of the Private Harley Street Clinic, said understanding the COVID-19 status of employees is crucial to business.
He said: “Dynamic organisations want to keep their workforce safe, and their offices open. They may want to implement a track and trace application that is fit for purpose and benefits their business.”
The clinic said tests should be part of an ongoing programme to detect and respond to cases and minimise transmission in the workplace.
Imperial College analysis said testing healthcare workers once a week would reduce transmission by a further 16-23% on top of self-isolation.
The clinic has also developed an app which uses wearable technology to track and trace employees and customers, with data stored locally to create a company-wide tracking system.
Yet Emilie Cole, partner and employment lawyer at Irwin Mitchell, warned employers they risk facing an increase in employment tribunals if they threaten staff that they could lose their job by staying away from work.
She said: “Everyone has the right to a safe place of work and if you raise health and safety concerns about that and you’re dismissed or subjected to detrimental treatment, you have a claim in the employment tribunal.
“I think there’s a potential for a lot of claims, but the reality is, do people have the stomach to bring them to a tribunal given their personal circumstances? If they have no other option, then they will.
“It’s all going to kick off after the furlough scheme starts winding down and the money runs out. There will be a lot of redundancies when that ends and it’s just prepping for that at the moment.”
The NHS is offering free tests to anyone with symptoms and has developed an NHS track and trace app for the general public.
Since the easing of lockdown, there have been clusters of cases in businesses across the country.
Vegetable pickers at a farm in Herefordshire are having to self isolate after more than 100 people tested positive for COVID-19.
Two workers told the BBC they had to share one toilet with up to 60 others at A S Green and Co, which went into lockdown after the tests.