An applicant can apply for a UK Ancestry visa if they qualify under one of the following categories: 1. Commonwealth citizen, 2. British overseas citizen, 3. British overseas territories citizen, 4. British national (overseas), 5. Citizen of Zimbabwe. The applicant is also required to prove that one of their grandparents was born in the UK, the Channel Islands, or the Isle of Man and must meet the other eligibility requirements as well.