Lateral Flow Testing in Workplaces

Information for businesses interested in introducing COVID-19 lateral flow testing for employees

Lateral flow testing can help to find cases in workplaces and stop the disease spreading.  Identifying cases early means larger outbreaks are less likely to happen, which protects people’s health and can protect your business – ensuring it can continue to operate.

You need to be ready to carry out tests properly, investing resources and time.  Remember, testing won’t identify all cases and all Government measures (such as Hands, Face, Space) still need to be in place and reinforced.

Do I need to notify anyone about positive COVID-19 cases in my workforce?

Yes, the MK local public health team.  Please complete this online form or call 01234 718141 (office hours Monday - Friday) or email (7 days a week). MK shares a public health resource with Bedford.

What is Lateral Flow Testing (LFT)?

Lateral flow testing is a quick way to test whether people have COVID-19. It is normally used to test people who do not have symptoms of coronavirus.  One in three people with COVID-19 have no symptoms and may be spreading it unknowingly. Testing people without symptoms is an important tool to identify those people and help to stop the virus spreading. Find out more.

What’s the difference between LFT and standard PCR tests?

In Polymerase Chain Reaction (PCR) testing a swab is used to collect a sample from the patient's tonsils and inside their nose. This is sent to a laboratory where it is tested for small fragments of the virus using specialist equipment. Because it needs to be sent away, the PCR testing takes longer, around one to two days.

LFT samples can be processed on site. The swab is inserted into a tube of liquid for a short time which extracts any COVID-19 virus. A few drops of liquid are added to a small strip of paper. Within 30 minutes, the strip will show up with two lines if it is positive, one line on the top if it is negative, or one line on the bottom if the test is invalid.  Watch a Department of Health video explaining the LFT testing procedure.

How do I access LFT for my workplace?

If you have fewer than 50 employees, any employees who can’t work from home can visit MK Council’s test centre at the Central Library every weekday. Find more details and opening hours.

If you have more than 50 employees, you can order tests for your staff.  Register an interest by emailing  or clicking here.  You must register by 31 March 2021. You’re welcome to contact MK Council to learn how our test centre works in order to shape your own plans.  Just email us on

How frequently should I test my staff?

To ensure you capture most people who are infectious, test everybody every 3-4 days.

What should a positive LFT case do?

  • Anyone who tests positive via LFT must self-isolate for ten days along with their household immediately.
  • You as the employer should keep a record to comply with workplace and NHS test and trace contact tracing. 
  • Identify close contacts. A close contact is a person who has been close to someone who has tested positive for COVID-19 anytime from 48 hours before the person was symptomatic, up to 10 days from onset of symptoms (this is when they are infectious to others).  Click to read a full list of who would be considered a close contact.
  • If the test was arranged privately (not via MK Council test centre, or by tests ordered from Government) you should arrange a confirmatory PCR swab test within 24 hours. (If it was a Government or Council test, it will automatically feed into the national test and trace system, triggering the legal duty to self-isolate, eligibility for support payments, and contact tracing.)
  • More information on how to manage COVID-19 Cases in the workplace.

What happens if an employee tests negative?

A negative test means the virus was not found in the swab. It is possible for Lateral Flow Tests to miss individuals who are early on in their COVID-19 infection, so while the employee does not need to isolate they must continue to take all Government precautions including social distancing, wearing a mask and regularly washing their hands. If they develop symptoms, they must isolate immediately, and book a standard PCR test at or by phoning 119.

Should staff who have tested positive be re-tested before they return to work?

No. Staff who have previously tested positive and completed their 10-day self-isolation should not be re-tested using LFT or PCR for a period of 90 days from their last positive test result. This is because these people will no longer be infectious and are therefore safe to return to work (once well) but may still have traces of the virus which would be detected by a test.

Should I test staff who have received a COVID-19 vaccination?

Yes. The vaccine offers them protection against COVID-19 but may not prevent the person from acquiring and passing on the virus to others.

Last Updated: 3 March 2021