Lateral Flow Testing in Workplaces

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.  

We know that a significant proportion who test positive for coronavirus have no symptoms and can therefore spread it unknowingly. So, testing people without symptoms is an important additional tool to identify people with the virus, and therefore stopping the virus spreading through communities.

Further Government guidance can be found here.

What is the difference between PCR and LFT types of testing for Covid-19?

PCR Testing (Standard test)

PCR stands for Polymerase Chain Reaction (PCR) testing. A swab is used to collect a sample from the patient's tonsils and inside their nose. This is then tested for small fragments of the virus called RNA.

This is then sent to a laboratory where it is processed using specialist equipment. Because it needs to be sent away, the PCR testing takes longer, around one to two days.

Lateral Flow Testing (Rapid Test)

As with PCR testing, Lateral Flow Testing (LFT) involves a swab being inserted into the nose or throat. However, instead of sending the sample away the sample 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 then dropped onto a small strip. Within 30 minutes, the strip of paper 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.

You can watch this Department of Health video explaining the LFT testing procedure.

How do I access LFT for my workplace?

Anyone in England who does not have symptoms can now get regular lateral flow tests to check for coronavirus. In Milton Keynes we are offering free rapid COVID-19 tests (LFTs) to anyone over the age of 16.

Home test kits: You can collect up to 14 free lateral flow devices from the Central MK Library, 555 Silbury Boulevard MK9 3HL. No need to book, show ID or register - just ask a member of staff.

Or use the following .gov website to order one pack of 7 lateral flow devices. Find out more here

Pharmacy collect: Find a local pharmacy where you can collect up to 2 packs of 7 rapid tests. Click on the following link and enter your postcode to find the nearest pharmacy to you 

On site tests: You can visit our Central MK Library for a free on site test. No need to book. Results will be sent to you within around 45 minutes.

The test centre is open weekdays from 9.30am to 4.30pm, and stays open later on Thursdays until 7pm.

Please note: No-one with symptoms can be tested at this site. Instead, anyone with one or more of these symptoms – a high temperature, a new, continuous cough, or a loss or change to sense of smell or taste – should book a test at or by calling 119.

For information on how to manage Covid-19 cases in the workplace please visit this link.

Does a positive case need to self-isolate?

Yes. Anyone who tests positive via a LFD must self-isolate along with their household immediately and their contacts will be traced. If a negative confirmatory PCR is obtained within 2 days of the positive LFD test result, the individual no longer needs to self-isolate and contact tracing will cease.

Please follow the most up to date Local Authority employers flow chart to manage cases and notify public health teams. These can be found here

How to notify the local Public Health team of a case (s) of COVID-19 in your workforce:

For queries and confirmed case reporting please contact our Public Health team responsible for COVID-19 on 01234 718141 (office hours Monday - Friday) or (7 days a week). Emergencies out of hours should be escalated to the Service Director who may contact the Director of Public Health.

Should people who have tested positive with a LFD go for a confirmatory PCR test?


As of 30th March 2021, all individuals who receive a positive LFD test result will be encouraged to take a follow-up PCR, whether the LFD test was assisted or self‑reported. 

For Assisted LFD tests: For LFDs undertaken under supervised conditions, a positive LFD result will trigger the legal duty to self-isolate and initiate contact tracing. If a negative confirmatory PCR is obtained within 2 days of the positive LFD test result, the individual no longer needs to self-isolate and contact tracing will cease. If the confirmatory PCR test is taken too late, the individual who got a positive LFD, (and their household) will need to self-isolate for the full 10 days. The PCR test can be taken at a test site or at home. 

Notification of a positive assisted LFD result or notification of being a contact will be treated, as now, as the trigger for access to the Test and Trace Support Payment (TTSP) (for those eligible).  The payment will not be recovered where there is a subsequent negative PCR result and those notifications are rescinded.


For Self-Reported LFD tests: For LFDs undertaken at home, the legal obligation will only commence once a positive PCR test is confirmed but anyone who has received a positive LFD result should still self-isolate (along with members of their household) as soon as they get the positive LFD. The PCR test can be taken at a test site or at home. 

Someone who self-reports a positive LFD result is asked to self-isolate immediately with other members of their household, but is asked to take a follow-up PCR test – and it is a positive PCR result that triggers the legal duty to self-isolate, access to TTSP (if eligible) and contact tracing. If a negative confirmatory PCR is obtained within 2 days of the positive LFD test result, the individual no longer needs to self-isolate and contact tracing will cease.

The employee and their household should isolate for 10 days starting immediately. You as the employer should keep a record and comply with workplace and NHS test and trace contact tracing. For information on how to Manage Covid-19 cases in the workplace, please visit this website

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, therefore although the employee does not need to isolate they must continue to take all precautions including social distancing, wearing a mask and regularly washing your hands.

Follow the latest Government rules at: 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?

A. No. Staff who have previously tested positive, via an LFT and a confirmatory PCR test, and have 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?

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

If an employee tests positive. Should I identify close contacts for self-isolation?

A. Yes. 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).

A full list of who would be considered a close contact can be found here -

Identifying close contacts of a positive case will help determine who may need to self-isolate for 10 days to help stop the spread of the virus.

What are the risks and benefits of testing for my workplace?

The benefits include:

  • Finding cases within the workplace stopping 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

The risks include:

  • Taking care to carry this out properly
  • Potential costs associated with a thorough testing programme – peoples time and resources
  • A risk that the testing won’t identify all cases and therefore ‘Hands, Face, Space’ measures still need to be in place and reinforced.
  • There will be a small number of people who have a ‘false positive’ (where people test positive but do not have the disease) and therefore some people will self-isolate unnecessarily. It is important to carry out LFT testing in your workplace under strict protocols to minimise the false positives and false negatives (missed diagnoses).

What support is available to help me set up Lateral Flow Testing in my workplace?

A member of the Community Testing team can give advice to ensure testing protocols are safe, effective and adhere to recommended testing guidelines

How frequently should I test my staff?

To ensure you capture most people who are infectious, you will need to test everybody every 3 to 4 days or twice a week.  

Last Updated: 9 June 2021