Visa or passport
Visa or British passport: which question comes first?
Understand the difference between permission to travel and evidence of nationality before choosing a route.
A passport and a visa answer different questions
A passport is a travel document associated with nationality and identity. A visa concerns permission for a particular purpose. A British connection may call for a nationality enquiry before a passport application; it should not be treated as a ready-made passport entitlement.
Begin with your own position
A person renewing a British passport starts somewhere different from someone investigating a British parent or planning a visit on a South African passport. Your existing nationality and intended activity help identify the useful starting point.