Track and Trace - could it affect us ?

Hypothetical question : If a customer attend's your mot station for a pre booked appointment for mot or service and then after the appointment, said customer contract's the corona virus and the Track and Trace system register's you as having been in contact with said customer .. would we then have to isolate for 14 day's ? .. We are keeping everything to the set out guidelines, but just thinking aloud, that if the customer was signed up to the app, would we be notified and would there be need to isolate ? 

Hope everyone is well and safe, have a great day, Paul ...