Your channel's phone number may automatically allow sending messages to international numbers, which could cause carrier or aggregator fees to add up. To avoid international messaging charges, you can choose to restrict sending.
First, navigate to your account page and scroll down to the phone number you'd like to restrict:
One the following page, click on the ☰ menu icon and select 'Edit':
Uncheck the box allowing sending to international numbers:
That's it! Questions? Send us a message via the support widget in the bottom right corner.