Sending SMS internationally through Twilio requires navigating a patchwork of carrier rules that differ by country in ways that are not always obvious from a US-centric compliance perspective. What is standard practice in the United States, such as using a 10-digit long code or a toll-free number for marketing messages, may be prohibited, technically impossible, or subject to strict pre-registration requirements in other markets. This checklist covers the most commonly used destination markets for Twilio business senders and the key requirements in each.
United States, Canada, and Mexico
In the United States, A2P 10DLC registration is mandatory for 10-digit long codes, toll-free verification is mandatory for toll-free numbers used in SMS, and short codes require separate carrier provisioning that can take 8 to 12 weeks. Canada requires compliance with CASL, which mandates express consent for commercial messages except where a specific implied consent exception applies within a two-year window from a prior business relationship. Canadian carriers do not have an equivalent of A2P 10DLC registration, but alphanumeric sender IDs require registration with individual carriers and are not universally supported. Mexico uses local long codes for domestic SMS, and international numbers attempting to deliver SMS to Mexican mobile subscribers face high filtering rates from Telcel and AT&T Mexico; local numbers provisioned in-country are required for reliable delivery. Mexico also prohibits unsolicited commercial SMS under its Federal Telecommunications Law, requiring documented opt-in consent from all recipients.
United Kingdom, Germany, and France
The United Kingdom regulates SMS marketing under PECR, which requires prior opt-in consent for marketing messages, and the Information Commissioner's Office actively enforces with fines that have reached several hundred thousand pounds for large-scale violations. Alphanumeric sender IDs are widely supported in the UK but must not impersonate emergency services, government agencies, or well-known brands. Germany applies its Telecommunications and Telemedia Data Protection Act alongside GDPR, and German carriers generally require international senders to use registered alphanumeric sender IDs that are pre-approved by the carrier for marketing traffic. Germany has some of the strictest SMS marketing standards in Europe, and German subscribers report spam at higher rates than most other European markets. France requires compliance with CNIL guidelines under GDPR, mandates that marketing SMS be sent only between 8am and 9pm local time on weekdays, and prohibits sending marketing SMS on Sundays or national holidays; these restrictions are enforced by French carriers at the network level and are not simply policy recommendations.
India, Australia, and Singapore
India's DLT registration system, administered by the Telecom Regulatory Authority of India, requires businesses to register their entity, all sender IDs, and every individual message template before those templates can be delivered to Indian mobile subscribers. Template registration must be completed on the DLT platform of the recipient's carrier, and with multiple carriers in India each having their own DLT portal, managing Indian SMS compliance requires registration on multiple platforms or working with an aggregator that handles multi-carrier DLT registration. Australia regulates commercial electronic messages under the Spam Act 2003, which requires expressed or inferred consent, sender identification in every message, and a functional unsubscribe mechanism. Australia's ACMA enforces violations with civil penalties of up to AUD 2.1 million per day for serious or repeated breaches. Singapore's Personal Data Protection Act requires opt-in consent for marketing messages and mandates that senders honor do-not-call registrations checked against the Do Not Call Registry maintained by the Info-communications Media Development Authority.
Brazil, Japan, and South Africa
Brazil's Lei Geral de Protecao de Dados, the Brazilian General Data Protection Law equivalent to GDPR, requires documented consent for processing personal data including phone numbers for SMS marketing. Brazilian carriers also require that commercial SMS be sent with sender registration, and international numbers face high filtering rates; local Brazilian long codes or short codes provisioned in-country produce significantly better delivery. Japan has some of the most restrictive commercial messaging laws in the world under the Act on Regulation of Transmission of Specified Electronic Mail, which effectively prohibits most forms of commercial SMS marketing to Japanese subscribers without a pre-established direct business relationship and explicit opt-in. Japanese carriers filter international marketing SMS very aggressively, and businesses that need to reach Japanese subscribers typically use native messaging apps or email rather than SMS. South Africa's Protection of Personal Information Act requires opt-in consent for marketing communications and gives the Information Regulator enforcement powers with civil penalties of up to ZAR 10 million for serious violations; South African carriers support alphanumeric sender IDs but require them to be registered with the carrier before commercial use.
Conclusion
International SMS compliance is a country-specific exercise with no universal shortcut, and the consequences of sending without proper local authorization range from carrier filtering to regulatory enforcement actions in each market. Speak with our compliance team and we will audit your Twilio setup for regulatory gaps at no charge and build a compliant sending framework for every country in your program.
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