Calling with the Caller feature is disabled in certain countries due to a high probability of fraud. These limitations are set by Twilio, our partner who powers the Caller feature.
Here are the countries with these limitations:
Saudi Arabia— Users in Saudi Arabia have some limitations using the Caller feature, such as not being able to make calls to Saudi Arabia from Saudi Arabia. For more information on these limitations, please read these guidelines. Users in the United Arab Emirates also have limitations with toll-free and geographic phone numbers, which can be found here.
Malaysia— Users may only be able to complete outbound calls to Malaysian numbers from a Twilio-supplied Malaysian number recognized by their telecom carrier partner as being on their network. This is due to some Malaysian telecom carries blocking any outbound calls from any Malaysian phone number that is not a phone number in an effort to reduce fraud and abuse on Malaysia's telecom network.
For more information on calling limitations, visit Twilio's calling regulations guideline.