The NHS COVID-19 app calculates how long you need to self-isolate for, depending on the reason you're self-isolating.
If you’ve had a ‘close contact’ alert
If you are a close contact of someone who has tested positive for COVID-19, you do not need to self-isolate if you are fully vaccinated, under 18 or taking part in a clinical trial. Fully vaccinated means your second dose needs to have been at least 2 weeks (14 days) ago, and with an approved vaccine. Fully vaccinated does not include booster vaccinations. To reduce risk, you should take and report a daily rapid lateral flow test for 7 days.
If you are not fully vaccinated, under 18 or taking part in a clinical trial, you will need to self-isolate if identified as a close contact of someone who tested positive for COVID-19.
You need to self-isolate for 10 full days from the date you were last in contact with the person; the ‘encounter date’. This means that if you were in close contact with someone who tested positive for coronavirus on the 1st of the month, you would need to self-isolate up to and including the 11th of that month.
If you have symptoms
If you're self-isolating because you have coronavirus (COVID-19) symptoms, and have entered these into the app, the app will use the day that you reported you first had symptoms to calculate how long you need to self-isolate. When you enter symptoms in the app it will ask you for the date they first started; the ‘symptoms onset date’.
If you said that you cannot remember when your symptoms started, the app will calculate your ‘symptoms onset date’ as 2 days before you reported symptoms into the app.
If you’ve had a positive test result
If you book a PCR test through the app, the app will automatically receive your test result. If you have previously reported symptoms in the app before booking a test, your isolation period will be calculated using the date you first had symptoms, so if you test positive this date will not change.
If you didn't book your PCR test through the app, or you tested positive on a rapid lateral flow test at home you can still enter your positive test result in the app.
The app calculates your isolation period as 10 days in addition to a 'Day 0' which is either the date the test was taken or the date you confirm your symptoms started. This means that if ‘Day 0’ is the 1st of the month, you would need to self-isolate up to and including the 11th of that month.
In England, you can leave self-isolation after 5 full days, as long as you test negative on day 5 and day 6. The first rapid lateral flow test must be taken no earlier than day 5 of your self-isolation period. You can then leave self-isolation on day 6 if both tests are negative and you do not have a high temperature. If either test is positive, you must continue to self-isolate until you get 2 negative rapid lateral flow tests taken on consecutive days, or you have completed 10 full days of self-isolation. If you leave isolation before the full 10 day period, you can disregard the app's countdown timer for the remaining days. It is a useful reminder to continue taking extra care during this period. You will not receive any close contact notifications until your 10-day count down timer ends.
In Wales, you can leave self-isolation after 5 full days. You are strongly recommended to take a rapid lateral flow test on day 5 and day 6 to check if you are still infectious. The first rapid lateral flow test should be taken no earlier than day 5 of the self-isolation period. Tests should be taken at least 24 hours apart. If either of the rapid lateral flow tests taken on day 5 or day 6 is positive or you have a high temperature, you should remain in self-isolation until you've had 2 negative rapid lateral flow test results or you have completed 10 full days of self-isolation, whichever is sooner.
If you receive negative lateral flow test results on days 5 and 6 and leave self-isolation, you can disregard the app's countdown timer for the remaining days. It is, however, a useful reminder to continue taking extra care during this period. You will not receive any close contact notifications until your 10-day count down timer ends.
If you leave self-isolation before 10 full days you are strongly advised to:
limit close contact with other people outside your household, especially in crowded, enclosed or poorly ventilated spaces
wear a face covering in crowded, enclosed or poorly ventilated spaces and where you are in close contact with other people even if it is for a limited time
work from home if you can
limit contact with anyone who is at higher risk of severe illness if infected with COVID-19
follow the guidance on how to stay safe and help prevent the spread.
If you test positive you'll also be contacted by the wider NHS Test and Trace or NHS Wales Test, Trace, Protect service. Contact tracers will use the date the test was taken or the date you confirm your symptoms started to calculate your isolation period.