The Business Registrations and Licensing Agency (BRELA)[ (http://www.brela.go.tz/] registers companies in Tanzania. Based on the data available on Open Corporates, it appears that BRELA assigns each organisation with a unique identifier .
"The Business Registrations and Licensing Agency (BRELA) is an Executive Agency under the Ministry of Industry and Trade responsible for business administration and regulation of the laws; namely Companies Registration, Business Names Registration, Trade and Service Marks Registration, granting of Patents and issuing of Industrial License." 
The Business Registrations and Licencing Agency (BRELA) has started to list registered companies in Tanzania through the Online Registration System (ORS) which can be searched for business and company names by the general public. Please note, however, that not all businesses may yet be present on the ORS as updated data or annual returns are required in order to populate the database.