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Thailand voice guidelines

Voice calling guidelines for Thailand (TH), covering reachability, caller ID formats, DTMF support, and emergency services.

Locale overview

FieldValue
CountryThailand
ISO codeTH
RegionAsia-Pacific
Dialing code+66

Reachability

Call typeInboundOutbound
DomesticSupportedSupported
InternationalSupportedSupported
Toll-freeSupportedNot supported

Using an Outbound Number that is not a ringDNA Smart Number is not supported for outbound calls to Thailand domestic numbers. Use a provisioned Thailand phone number for domestic outbound calls. Outbound calls from toll-free numbers are not allowed.

Caller ID

Call typeDirectionFormat
DomesticInbound+E.164
DomesticOutboundLocal
InternationalInbound+E.164 (non-guaranteed)
InternationalOutbound+E.164
Toll-freeInbound+E.164
Toll-freeOutboundN/A

DTMF support

DTMF is supported using RFC 2833 for both inbound and outbound calls.

Emergency services

Calls to emergency services are not supported in Thailand.

Compliance note

These guidelines summarize carrier requirements at the time of publication and do not constitute legal counsel. Verify that your implementation complies with all applicable telecommunications regulations in Thailand.