Guidelines

Vietnam (VN)

Locale Summary
Locale name	Vietnam
ISO code The International Organization for Standardization two character representation for the given locale.	VN
Region	Asia
Dialing code The dialing prefix used to establish a call or send an SMS from one locale to the given locale.	+84

Reachability Can Twilio complete calls to numbers in this locale?	Inbound Ability to call numbers. Calls are inbound from PSTN to Twilio numbers.	Outbound Ability to call non-Twilio numbers. Calls are outbound from Twilio to PSTN numbers.
Domestic For calls within the locale	No	No
International Can in-locale numbers be reached from outside the locale?	Yes	Yes
Toll-Free Can in-locale Toll-Free numbers be reached from within the locale?	Yes	No
Outbound restrictions Regulatory and/or Carrier restrictions on outbound calls made from Twilio to non-Twilio numbers in this locale	Twilio does not offer Vietnam Local Numbers. Calling to Vietnam from a registered caller ID (Non-Twilio +84 number) is best effort / not guaranteed. Outbound calls from Toll Free numbers are not allowed
Outbound requirements Conditions that must be met before outbound calls are allowed from Twilio to non-Twilio numbers in this locale	Please use an International Twilio number to make outbound calls to Vietnam.
Best practices Useful tips for best performance on outbound calls to non-Twilio numbers in this locale	N/A

Caller ID Can Twilio complete calls to numbers in this locale?	Inbound Inbound call receives originator's Caller-ID. Calls are inbound from PSTN to Twilio numbers.	Outbound Outbound call preserves sent Caller-ID. Calls are outbound from Twilio to PSTN numbers.
Domestic For calls within the locale	N/A	N/A
International Can in-locale numbers be reached from outside the locale?	+E164	+E.164 (Not guaranteed)
Toll-Free Can in-locale Toll-Free numbers be reached from within the locale?	+E164	N/A

DTMF	Inbound Inbound call receives DTMF from PSTN. Calls are inbound from PSTN to Twilio numbers.	Outbound Outbound call sends DTMF to PSTN. Calls are outbound from Twilio to PSTN numbers.
RFC.2833 format Is RFC.2833 DTMF format supported?	N/A	Yes (Not guaranteed)

Emergency Calling Calls are outbound from Twilio to Emergency (911/933) numbers.	Outbound Ability to make Emergency Calls. Calls are inbound from PSTN to Twilio numbers.
Emergency services Are calls to Emergency Services Numbers in the locale allowed over Twilio?	No

For the benefit of all our customers, these guidelines are provided to help you comply with applicable requirements and to help ensure Twilio's platform remains compliant with global telecommunications ecosystem requirements. These guidelines represent our current understanding of common compliance requirements generally applicable to Twilio and its customers, and do not constitute legal advice. By posting these guidelines, Twilio makes no assurances regarding the legal compliance of your application built using our APIs. You are expected to understand and abide by all compliance obligations applicable to your specific application. You should check these pages regularly for updates as telecommunications ecosystem requirements continue to evolve and change, and the information below may be updated or changed without notice.