Switch residence/work permit

Hello all,
If I get residence/work permit class B and I want to do business in Tanzania, can I apply for residence/work permit class A there? is it in general possible to switch permit while being already in Tanzania?

Thank you

Thanks.

Class B permit is specific for the employement, which allows him/her to work in specific mention company. Whereas you will disallowed to do any business activity.

Secondly, you can't switch or transfer the class in between. You have to apply from the start if your intention or purpose of living is change.