Good Afternoon Nehimba,
I was able to find this information so hopefully this can help answer your query:
'The national currency of Namibia is the Namibian Dollar (NAD). This is linked on a one to one exchange with the South African Rand. The Rand is legal tender in Namibia Dollar. If you are wishing to purchase currency before arriving in Namibia it is easiest to buy Rand as the Namibian Dollar is seldom available in banks outside of Namibia.
It is advisable to visit Namibia with Rand in your pocket, and make sure you exchange any Namibian dollars you have back to Rand before you leave the country.
Credit cards are accepted at most supermarkets, restaurants and accommodation establishments in urban Namibia (Visa and Mastercard are most commonly accepted) but outlets in rural areas are more likely to only accept cash payment. Although ATMs can be found in most towns, it’s worth making sure that you’ve got enough cash handy at all times, as towns can be few and far between. Make sure you notify your bank of your travel plans before you go: Namibia is among the countries that trigger an automatic account freeze (fraud protection) if you fail to tell your bank beforehand.'
Kind Regards,
Amy