What do I do if the test shows an invalid result?

The test result is invalid if no line appears on the test cassette or if only a line appears at the Ag mark (antigen) or T mark (test line). In this case, the test is invalid and a new test must be done with a completely new test kit. If it happens with several tests in a pack, take the tests back to your distributor. Contact your doctor or your COVID-19 test centre.