If you have a positive test result, your contacts will be traced by NHS Test and Trace. They will be required to self-isolate until ten days after their most recent contact with you, unless they are participating in the specific trial of regular testing for contacts – in which case they will be given specific instructions on what they can and cannot do during this period.
If you have a positive antigen test but get a negative result on the PCR test, your contacts do not need to be traced.
If you have a negative or unclear (or “could not read sample”, “void”, “borderline” or “inconclusive”) result, your contacts do not need to be traced.