The government has changed the process at KIA, DAR, ZNZ airports.
Visas are still available on arrival but following the new process as below:
1.Queue for a Government Control number which is required for any government payment
2.Queue to pay the visa fee against the control number at the bank at the airport
3.Queue for immigration to check and issue the visa
The process could take in excess of 2 hours to complete!
We highly recommend you to obtain a visa before departure at the nearest Tanzania embassy or via the e-visa portal (link here) to avoid the long delay on arrival. The immigration services have advised that most visas are issued within 2 to 3 weeks of the application via the e-visa system.