You will need a passport with a minimum 6 months remaining validity at the completion of the trip. 

If you don't have a passport, apply for one in good time. If you do have a passport, check the expiry date. British Citizens can find more about passport applications at ips.gov.uk.

You will need a visa for entering Tanzania. For most travellers this is $50 but for some reason US citizens get to pay $100. If you are flying direct to Tanzania it is possible to purchase your visa on arrival at Kilimanjaro International Airport The queue however can be very long and Tanzanian adminstration is painfully slow so if you have a low patieince threshold save yourself an hour by getting your visa in advance. Information on how to apply can be found here Tanzanian Visas

You should also note the Tanzanian High Commission does advise visitors to apply for visas in advance as they reserve the right to deny you a visa on arrival. Having said that we have never ever heard of this happening.

Although we make every effort to keep this information up to date, we ask you to double check the requirements, either with the relevant consulate or Embassy, or by using a visa agency such as www.thevisacompany.com

Each individual traveller is responsible for ensuring that they have a valid passport and all relevant visas for their holiday.