Here are the documents you need to apply for a Namibian visa:
A valid passport that is still good for at least six months.
You can get the visa application form from the Ministry of Foreign Affairs' website or from a travel agent in Namibia.
Two photos taken within the last six months for your passport.
Proof of money, like an international bank statement, proof of income, or a letter from your employer saying how much you make and how long you will be in Namibia.
If your visa application is not in English, it will be turned down.
Imagine that you want to get a business visa. In that case, you will also need to show proof that your business has been operating legally in Namibia for at least three years before you send in your application.