You can find information on free testing via the NHS here. The Gov website releases free COVID-19 tests regularly throughout the day so keep refreshing the site every hour. You need to get a test within the first 5 days of showing symptoms (high temperature, new continuous cough and a loss or change in your sense of smell).
You can obtain a free test via the GOV website
You can pay for a COVID-19 test at CityDoc
You can pay for an at-home COVID-19 test at London Doctors Clinic
Still stuck and can’t find a test? Email firstname.lastname@example.org and we will help you!
If you suspect that you have already had COVID-19, there are lots of paid-for antibody tests available online including via BUPA that will confirm if you have already had COVID-19 or not.