The U.S. State Department provides a complete list of your federal benefits and obligations at https://travel.state.gov/content/passports/en/abroad/legal-matters/benefits.html
Residents of Namibia that have questions regarding benefits or services from U.S. Federal Agencies, such as the Social Security Administration (SSA), should contact the Federal Benefits Unit in London. The London Federal Benefits Unit web site provides information you will find useful.
The best way to contact the London Federal Benefits Unit is via their online form at the above link. You should receive a reply within 3 business days.
If necessary, you can write to the London Federal Benefits Unit at the following address:
Federal Benefits Unit
24 Grosvenor Square
London W1A 2LQ
Another option is to call the London Federal Benefits Unit Monday through Friday between the hours 8:30am and 1:00pm (London Time) at +44-020-7499-9000, extensions 2926 or 2927. If you cannot dial extensions directly please listen carefully for the automated switchboard option of "Federal Benefits Unit".
Social Security Numbers
If you are applying for a Social Security number, you should review the documentation requirements. You should then complete the form SS-5 (PDF, 237kb) Application for a Social Security Card, and bring the required documentation, ORIGINAL documents only, to the U.S. Embassy in Windhoek, by appointment only, for review, document certification, and forwarding to the Federal Benefits Unit in London for processing.