Bulk SMS in Thailand requires a registered sender ID: under NBTC rules published in August 2025, A2P SMS may only come from registered senders, unregistered ones are fully blocked since 6 October 2025, and links must be registered too. VoIP in Thailand is licensed by the NBTC, and incoming international calls now carry a +697 or +698 warning prefix that users can choose to block.
Rules last checked: October 2026.
Bulk SMS in Thailand: NBTC sender ID registration
New NBTC rules, published in the Royal Gazette on 29 August 2025 and effective immediately, tightened SIM registration, SMS and international calls. For A2P SMS as of 2026:
- messages may only be sent from registered sender IDs; full blocking of unregistered sender IDs started on 6 October 2025;
- registration takes about two weeks through your provider, and dynamic sender IDs are not supported;
- operators may deactivate a sender ID that stays unused for a long time, which then needs registering again;
- operators must check that links are genuine before delivering the message.
| Sender type | Status in Thailand as of 2026 |
|---|---|
| Registered alphanumeric | The standard for A2P |
| Thai long code | Supported domestically |
| International long code | Not supported |
See sender ID registration by country.
URLs, sending hours and restricted content
- URLs: register the full URL together with the sender ID. Shortened URLs are prohibited and cannot be allowlisted. Links must lead to a legitimate site and must not open a download or a form asking for input.
- Banks: banks and financial services should not put links in SMS at all.
- Hours: promotional SMS is not allowed between 21:00 and 09:00.
- Content: gambling, adult content, political and religious content, firearms, controlled substances and alcohol are refused; loan offers need a Bank of Thailand licence.
- Consent: get opt-in consent and offer an opt-out, in line with Thailand's Personal Data Protection Act.
More in SMS content restrictions.
Thai mobile networks
The networks are AIS, True (merged with dtac) and NT (National Telecom). AIS lets subscribers block SMS from foreign numbers. Thai script is sent in Unicode, so one SMS holds 70 characters (GSM-7 vs Unicode).
VoIP in Thailand: licensing and numbering
VoIP is legal in Thailand for licensed providers. The National Broadcasting and Telecommunications Commission (NBTC) issues telecom licences and manages numbering, and international voice services need an NBTC licence. Bangkok numbers start with 02, mobile numbers mostly with 06, 08 or 09, and freephone with 1800. Mobile and fixed are priced separately on rate decks (mobile termination rates).
CLI rules and anti-scam measures in Thailand
The same August 2025 rules target scam call centers operating from across the border:
- incoming international calls are shown with a +697 or +698 prefix as a warning, and users can choose to block them;
- devices that hold four or more SIM cards (SIM boxes and gateways) must be registered with the NBTC, and unregistered devices are cut off;
- SIM cards must be verified, with limits on SIMs per foreign national;
- operators must suspend suspicious mobile services within 24 hours when the NBTC orders it.
For buyers: calls from abroad cannot pass as local Thai calls, and answer rates for international CLI are lower because users block the warning prefixes. Clean routes need KYC and a clear traffic type. See SIM box bypass fraud and CLI spoofing rules.
What buyers ask for on Thai routes
- Rates for fixed and for AIS, True and NT mobile, plus ASR and ACD.
- How the CLI is presented to the called party.
- For SMS: who handles sender ID and URL registration, lead time and OTP latency per network.
Check coverage on the Thailand VoIP destination page and the Thailand SMS destination page, or read about our VoIP termination and A2P SMS routes. VoIPMatcher sources the route from its carriers and manages it; buyers and sellers never see each other. Request a Thailand voice route or request a Thailand SMS route.
Frequently asked questions
How long does sender ID registration take in Thailand?
About two weeks through most providers. You submit the sender ID, your company documents and any full URLs you plan to send. Unregistered sender IDs have been fully blocked since 6 October 2025, so finish registration before launch and keep the ID in regular use, because long-unused IDs can be deactivated.
Can I use a URL shortener in SMS to Thailand?
No. Shortened URLs are prohibited in Thai A2P SMS and cannot be allowlisted. Register the full URL together with your sender ID, make sure it opens a legitimate page, and avoid links to downloads or forms. Banks and financial services should not include links at all.
What do +697 and +698 mean on calls in Thailand?
They are warning prefixes Thai operators add to incoming international calls under NBTC rules from August 2025, so users can tell a call comes from abroad. Users can choose to block calls with these prefixes. They do not mean every such call is fraud, but businesses calling Thailand from abroad should expect lower answer rates.
When can I send marketing SMS in Thailand?
Promotional SMS is not allowed between 21:00 and 09:00 Thai time, so schedule campaigns in daytime. OTP codes and service notices can be sent at any time. Marketing also needs the recipient's consent under the Personal Data Protection Act, and every message should allow an easy opt-out.
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