Question
What are the calling restrictions for toll-free numbers?
Answer
Inbound
Toll-free numbers should be used for domestic inbound voice calls only. If you try to call a toll-free number from a phone number outside that number's country, your call might not go through because these numbers are usually set up to work only within their own country.
Outbound
Outbound calls aren't supported from toll-free numbers, this also applies to numbers added as external numbers.
Since callback and overflow features rely on making outbound calls and toll-free numbers can't do that, you'll want to turn those features off.
Note: While Zendesk doesn't support outbound calls from toll-free numbers, in some cases outbound calls can be made. However, Zendesk cannot guarantee that the Caller-ID won't be modified. To make outbound calls in Zendesk Talk you need a number capable of making outbound calls that is not toll-free.