Surge testing for South Africa Covid variant extended to Finchley, Barnet Volunteers will collect Covid-19 test kits from residents in a targeted postcodes in the area as part of the surge testing operation (Getty Images) Surge testing is set to take place in the London borough of Barnet after one further case of the South Africa Covid variant was detected. Health officials will launch targeted testing for certain households in the Finchley area from tomorrow. People living in the N3 postcode and those who shop on Barnet High Street will be asked to take extra tests. numbers. Households will either get a leaflet asking them to get a test from a specially deployed mobile testing unit, or be asked to complete a home kit by a door-to-door team.