Tanzania uses two currencies, USD and Tanzanian shilling, but a visitor can bring any amount of foreign currency. To exchange money in a Banks or Authorized Forex office operating at the international Airport, major towns, and border posts you will have to show your passport. Banks have fair exchange rates but do not exchange money on the street.
For local shopping and smaller expenses, it’s best to carry shillings. Prices in dollars are oftentimes quoted higher than in Tanzanian Shillings, therefore is good to exchange the dollars to TSH.