We would advise you to drop off your sample to us or by the laboratory as early as possible, such that it is just within the time window required by your airline. For instance, if the test needs to be no more than 72 hours before your flight, then take a sample and deliver it to the lab exactly 72 hours before your flight.
You are welcome to collect your sample kit in advance and then only take the sample and deliver it to the lab at the exact time required. Samples can be dropped off at the laboratory in Harley Street, 7 days a week. Instructions on how to collect your sample and return it to the lab and collect your results will be discussed at your convenience.