Well I doubt it would be 100% accurate, you bet you read he small print and it will say something along the lines of not to be used seriously, or if you want true result you need to see a specialist blah, blah blah.
I have had a look at the Terms and Conditions. Within those there is a link to this document.
External Link/Members OnlyIt details how they handle the samples and do the testing. It includes tables containing figures for the accuracy levels of each of the tests.
Incidentally, it also includes the outline of the messages they send out -
For positive patients, “Hi {First Name}, the results for your test ({Specimen Code}) are now available, please call {Local Provider Number} to collect your results as soon as you can.”
Negative patients will be contacted with the message “Hi {First Name}, you'll be glad to know your test ({Specimen Code}) came back all clear! See freetest.me for more details.”