Testing FAQs

General FAQs

How many different types of tests are there and what’s the difference between them?

There are two main types of test used to check if people currently have coronavirus.

The first type of test is known as a polymerase chain reaction (PCR) test, and looks for the virus’s genetic material (RNA).

The second is called a lateral flow antigen test (LFT), which looks for parts of the surface of the virus.

Are lateral flow tests less accurate than PCR tests?

Lateral flow and PCR tests have different characteristics and different uses. PCR tests have higher specificity and sensitivity but require a laboratory to process results and are therefore slower and more expensive. They are therefore well suited to specific use cases, such as those with Covid symptoms.

While lateral flow tests have lower sensitivity than PCR, they deliver results far faster and do not require a lab, making them more scalable. As such, they allow us to test far larger numbers of people without symptoms and get them their test result faster than with PCR technology. This will enable us to capture a large percentage of people who are infected and infectious, but have no symptoms and are unaware of the fact that they are possibly spreading Covid.

Can I book either test in order to get a travel certificate?

No, you should not use this service to get a test in order to travel to another country. We do not provide certificates for travel purposes. You can pay for a private test.

I received a negative test result, do I still need to follow the rules?

Both tests can only look for virus at the time you test. It is therefore essential that even if you test negative you continue to follow the rules: Hands, Face, Space and Fresh Air.

Can I get financial support if I test positive?

If you test positive after taking a COVID-19 test, you may be entitled to a £500 Test and Trace Support Payment.

>> Find out more and apply for a £500 Test and Trace Support Payment


Symptom-free testing FAQs

What is the lateral flow testing technology?

LFT technology is a point of care antigen test which uses a throat and/or nasal swab sample. An antigen test looks for parts of the surface of the virus (antigen) collected via nose and throat swabs and saliva samples.

Lateral flow technology does not require a lab setting as samples are processed on-site. LFTs can therefore be rapidly deployed across multiple locations.

Do these tests work for people without symptoms?

Lateral flow tests are safe, inexpensive and the results are trusted. Extensive research from Public Health England and the University of Oxford show LFTs are specific and sensitive enough to be deployed for mass testing, including for people without symptoms.

What will this test tell me?

If you get a positive result, it is likely that you were infectious at the time the test was taken. The antigen test cannot detect very low levels of coronavirus in a sample, so if you have only recently been infected, are in the incubation period, or if you have mostly recovered, the test may not give a positive result.

How long does it take to do the test?

It takes less than 15 minutes to administer the test.

How long does it take to get the result?

The test produces a result within 40 minutes.

How are the tests processed?

Lateral flow devices do not require a laboratory to process the test. They can be processed at the testing site by trained personnel, which is why results are available more quickly.

Should I book an LFT if I’ve got symptoms of coronavirus?

Lateral Flow Tests are only for those without symptoms of the virus. If you have symptoms, you should book a PCR test.

Should I book an LFT if I’ve been told to self-isolate because I’ve been in close contact with someone who has tested positive?

If you have been in close contact with someone who has tested positive for COVID-19, you should not book a Lateral Flow Test. You must stay at home and complete 10 days self-isolation. Your isolation period includes the date of your last contact with them and the next ten full days. Taking a Lateral Flow Test will not allow you to end your isolation early. If you develop symptoms while you are self-isolating you should book a PCR test.

It's a legal requirement to self-isolate if you test positive or are told to self-isolate by NHS Test and Trace. You could be fined if you do not self-isolate.

Why should I get a test if I feel well?

You should get tested, even if you feel well, as 1 in 3 people who have COVID-19 show no symptoms but could be sharing the virus with loved ones and around the community without knowing.

Get tested, even if you feel fine to protect your family and loved ones, reduce the spread and keep Brent safe.

How many tests should I have?

You will need to book two tests, two to four days apart, in order to ensure the results are completely reliable. We recommend you do this regularly to help stop the spread of the virus.

Everyone should get tested twice weekly.

How can I cancel or change my appointment if I can no longer attend? 

There is a link in your booking confirmation which will allow you to cancel or change your appointment.

If you can no longer attend your appointment, we recommend you change your appointment rather than cancel as it’s important that you get tested.

Is the use of Ethylene Oxide in Covid-19 tests safe?

Lateral Flow Tests (the tests for people without symptoms of Covid-19) are sterilised using Ethylene Oxide to ensure they are safe to use. Ethylene Oxide is one of the most commonly used sterilisation methods in the healthcare industry to keep medical devices safe. Any traces of Ethylene Oxide left in the tests or packaging after sterilisation is not dangerous and is in line with international standards. There is also no link between Covid-19 testing and cancer. The Lateral Flow Tests used in schools and in the community have been fully tested and are completely safe to use on a regular basis.

Why do I need to get a confirmatory PCR test if I test positive after taking a rapid LFT?

Confirmatory PCR testing is to be reintroduced for all positive rapid results tests to allow positive cases to be traced sooner and help stop the spread of variants in the UK. The Government has announced that new technology, known as 'genotype assay testing', could halve the time it takes to identify if a positive COVID-19 test contains a variant of concern. Genotype assay testing can only be used with PCR tests, so their reintroduction in England will be used to validate the results of the initial lateral flow tests.

Also, as Dr Susan Hopkins of Public Health England (PHE) explains, when case numbers are low, the probability of a false positive from an LFT is higher and so asking people to confirm a positive LFT result with a PCR test will help avoid people needing to self-isolate unnecessarily, while maintaining the benefits of rapid testing to find true positive cases and for confirming when people are not infected.