Related to https://docs.whmcs.com/Usage_Billing
It would be useful if we can set customers (as a flag ON/OFF per service in order, not globally per customer) to a prepaid billing. Users can add credit to increase their balance, when the available credits are run out, the services are suspended and if the service still suspended in 5 days in a row, the service is terminated (Configurable ON/OFF per service in order)
For example, somene add to their account $10 USD
And they start consuming bandwitdh defined at $0.1 USD / GB Month, when they consume 100 GB, the service is suspended, because the run out of available credit, this example, assuming the bandwith is the only metric that is consuming credits.
I sent this inittialy as a ticket to whmcs, they said (@Dan Rodgers):
Users can topup their account which is then automatically applied to invoices, but the invoice would currently only be raised once per month and can exceed the credit on their account.
However I can see how the option to cut off services when amount consumed exceeds credit balanace could be useful.