Wialon CMS and Wialon interface both use the same API.
Please be clear on what exactly you need to achieve. Wialon CMS has a billing module that does control the use of various features and block accounts based on days and usage.
Billing is a very broad term, more specifics will be required to asnwer weather this can be a matter properly using Wialon CMS or actually integrate with 3rd party system.
If you provide exact requirement, with schema of data structure perhaps we may also be able to provide you a solution using Wialon API.
Nishad Hussain Kaippally
Implementation Specialist, Middle East, Gurtam
"Computer science is no more about computers than astronomy is about telescopes."