If you live in Namibia or are visiting then you can contact the British High Commission in Namibia which is located in the capital city of Windhoek. You can also contact them for assistance such as marriage registration, birth abroad registration or other consular assistance.
British High Commission Windhoek
116 Robert Mugabe Ave, P.O. Box 22202
Monday to Thursday: 8 am to 1 pm and 2 pm to 5 pm; Fridays 8 am to 12 pm
Monday to Thursday: 8am to 12 pm and 2 pm to 3:30 pm; Fridays: 8 am to 11 am