You'll notice that voice minutes cost different rates depending on whether they are incoming, outgoing, or incoming to Twilio toll-free numbers. Your voice minutes across all these types of calls will contribute to the volume pricing minimum requirement.
To give an example, let's say in the month of July, your account had the following usage:
200,000 inbound local minutes x $0.0085/min = $1,700.00. 200,000 outbound minutes x $0.013/min = $2,600.00. 100,000 toll-free minutes x $0.022/min = $2,200.00.
At this point, you've used 500,000 minutes and spent $6,500.00.
The next minute you use will be charged at the volume rate. If that's an inbound minute, it would cost $0.0080. Let's say your remaining usage for the month is 1,000 inbound minutes. Those would be charged as 1,000 x $0.0080/min = $8.00. So your voice usage costs for the month of July would be $6,580.
Numbers are charged to your account monthly, on the same day of the month as the day you bought them. So, even if the numbers you have in your account exceed the monthly pricing requirement, you may not see the pricing kick in until after the minimum quantity of phone numbers have been charged their monthly fee.
Volume pricing on phone numbers will take effect after charging 1000 numbers. This can be a combination of local numbers and toll-free numbers.
To give an example, let’s say in the month of July, your account had the following phone number charges:
800 local numbers x $1.00/number = $800. 200 toll-free numbers x $2.00/number = $400.
At this point you’ve been charged for 1,000 phone numbers and spent $1,200.
The next number you purchase will be charged at the volume rate. If that’s a local number, it would cost $0.50. Let’s say your remaining phone number purchases for the month include 100 local numbers. Those would be charged as 100 x $0.50/number = $50. So your phone number charges for the month of July would be $1,250.