No double-leg billing
Double billing is a common pratice in toll-free virtual pbx services. An incoming toll-free call is treated as one leg and the outbound call to a local number where the call is connected is treated as the second leg.
Each leg is charged seperately. This is often referred as double-leg billing. If the price quoted is 6.9 cents a minute, you are actually charged 13.8 cents for the call.
800PBX does not charge for double-legs and maintains a consistent rate for both the legs. Infact, this double-leg rate is even less than a single leg (incoming toll-free) charge by 800PBX’s competitors.

Toll-Free Virtual PBX Provider - 800PBX » Questions to ask your toll-free virtual pbx provider? said,
April 19, 2007 @ 4:36 am
[…] Check for double-billing and cancellation charges: Most of them double bill and you may want to stay away from these providers. This will save you from surprises and hidden […]