Free tool · Messaging
SMS rules by country
We list the SMS rules we could verify in each country, with the regulator or operator source and the date we last checked it.
Argentina SMS rules
| Topic | Rule | Type | Last verified |
|---|---|---|---|
| Content | Personal data may be used for advertising only with the data subject's consent. The data subject may at any time ask for their name to be removed or blocked from the advertising databases used for promotional messages. | Regulation | · Ley 25.326, art. 27 · InfoLeg, Ley 25.326 (texto actualizado) |
We list the rules we could verify. A topic with no verified rule is left out, not guessed. This is reference information, not legal advice; check the regulator link and the last-verified date.
Brazil SMS rules
| Topic | Rule | Type | Last verified |
|---|---|---|---|
| Content | A provider may not send promotional text messages without the consumer's prior, free and express consent. The consumer may cancel receipt at any time with the provider. | Regulation | · Anatel — Resolução nº 765/2023, art. 3º, XVIII (Regulamento Geral de Direitos do Consumidor) · Anatel, Resolução nº 765 de 6 de novembro de 2023 (RGC) |
We list the rules we could verify. A topic with no verified rule is left out, not guessed. This is reference information, not legal advice; check the regulator link and the last-verified date.
Chile SMS rules
| Topic | Rule | Type | Last verified |
|---|---|---|---|
| Sender | From 13 August 2025, mass text messages must use numbering assigned by Subtel: the 600 prefix for communications the recipient consented to, and the 809 prefix for unsolicited communications. | Regulation | · Subtel, Oficio Circular Nº 575/2025 (Resolución Exenta Nº 1.319/2004) · Subtel, Oficio Circular Nº 575/2025 (2025) |
| Content | A mass text message counts as solicited only when the recipient has given prior and unequivocal consent. An opposition or revocation under data-protection law ends that consent for future messages. | Regulation | · Subtel, Oficio Circular Nº 575/2025, definitions and section 6 (Ley nº 19.628) · Subtel, Oficio Circular Nº 575/2025 (2025) |
We list the rules we could verify. A topic with no verified rule is left out, not guessed. This is reference information, not legal advice; check the regulator link and the last-verified date.
Colombia SMS rules
| Topic | Rule | Type | Last verified |
|---|---|---|---|
| Content | Senders of commercial or advertising text messages must consult the National Excluded Numbers Register (RNE) and must not contact consumers registered there. Consumers may cancel receipt at any time. | Regulation | · Ley 2300 de 2023, art. 5 (read with the CRC-operated RNE) · Colombia, Ley 2300 de 2023 (2023-07-10) |
| Send window | Advertising text messages may only be sent Monday to Friday from 07:00 to 19:00. | Regulation | · Ley 2300 de 2023, arts. 3 and 5 · Colombia, Ley 2300 de 2023 (2023-07-10) |
| Send window | Advertising text messages may only be sent on Saturdays from 08:00 to 15:00. No advertising text message may be sent on Sundays or public holidays. | Regulation | · Ley 2300 de 2023, arts. 3 and 5 · Colombia, Ley 2300 de 2023 (2023-07-10) |
We list the rules we could verify. A topic with no verified rule is left out, not guessed. This is reference information, not legal advice; check the regulator link and the last-verified date.
Hong Kong SAR China SMS rules
| Topic | Rule | Type | Last verified |
|---|---|---|---|
| Sender | A commercial electronic message must carry clear and accurate sender information, and the sender must not hide the calling line identification when sending from a telephone or fax number. | Regulation | · OFCA, Unsolicited Electronic Messages Ordinance · OFCA, Unsolicited Electronic Messages Ordinance (fully commenced 2007-12-22) |
| Content | A commercial electronic message must include an unsubscribe facility and statement, and the sender must honour an unsubscribe request within 10 working days. A message must not be sent to a number on the Do-not-call Register without the user's consent. | Regulation | · OFCA, Unsolicited Electronic Messages Ordinance · OFCA, Unsolicited Electronic Messages Ordinance (fully commenced 2007-12-22) |
We list the rules we could verify. A topic with no verified rule is left out, not guessed. This is reference information, not legal advice; check the regulator link and the last-verified date.
India SMS rules
| Topic | Rule | Type | Last verified |
|---|---|---|---|
| Sender | Commercial text messages may only be sent using a header registered with the access provider for that sender. A subscriber that is not registered to send commercial communications may have its telecom resources capped or disconnected. | Regulation | · TRAI, TCCCPR 2018, regulations 3 and 10 · TRAI, Telecom Commercial Communications Customer Preference Regulations, 2018 |
| Content | A commercial text message may be sent only in line with the recipient's registered preferences or digitally registered consent. Consent can be revoked at any time. | Regulation | · TRAI, TCCCPR 2018, regulation 9 and the consent provisions · TRAI, Telecom Commercial Communications Customer Preference Regulations, 2018 |
| Send window | By default, customers block commercial communications from 21:00 to 06:00. The open default band is 06:00 to 21:00; customers may opt in to the blocked bands. | Regulation | · TRAI, TCCCPR 2018, schedule on time-band preferences · TRAI, Telecom Commercial Communications Customer Preference Regulations, 2018 |
We list the rules we could verify. A topic with no verified rule is left out, not guessed. This is reference information, not legal advice; check the regulator link and the last-verified date.
Mexico SMS rules
| Topic | Rule | Type | Last verified |
|---|---|---|---|
| Registration | Every mobile line must be linked to an identified holder before service is enabled. SIMs that cannot make voice calls, send SMS or make internet calls are exempt from the linking requirement. | Regulation | · CRT — Lineamientos para la Identificación de Líneas Telefónicas Móviles (DOF, 8 Dec 2025) · CRT, Lineamientos para la Identificación de Líneas Telefónicas Móviles (DOF, 2025-12-08) |
| Content | A consumer registered in the REPEP must stop receiving advertising calls and text messages within 30 days of registration. If promotional texts continue after that period, the consumer can report the provider to PROFECO. | Regulation | · PROFECO — Registro Público para Evitar Publicidad (REPEP) · PROFECO, Invita Profeco a inscribirse al REPEP para evitar llamadas publicitarias (2024-12-31) |
| Content | A provider may not send promotional text messages about additional services, plans or third-party advertising to its own subscribers unless they have given express consent. Consent may be revoked at any time without penalty; the provider must make the revocation effective within five business days. | Regulation | · NOM-184-SCFI-2018, clause 4.9 · DOF, NOM-184-SCFI-2018 (published 2019-03-08) |
We list the rules we could verify. A topic with no verified rule is left out, not guessed. This is reference information, not legal advice; check the regulator link and the last-verified date.
Peru SMS rules
| Topic | Rule | Type | Last verified |
|---|---|---|---|
| Content | Promotional text messages may not be sent unless the consumer first contacts the provider and gives prior, free, informed, express and unequivocal consent. Consent may be revoked immediately, at any time and without giving a reason. | Regulation | · Ley nº 32323 (2025), amending Ley 29571 art. 58.1(e) · El Peruano, Ley nº 32323 (2025-05-09) |
| Sender | SMS exchanged between networks must carry the originating number assigned under the national numbering plan: eight digits for a fixed line and nine for a mobile line. Masking the origin with an alphanumeric name is not allowed. | Regulation | · OSIPTEL, Informe nº 086-2026-DPRC, citing MTC Oficio nº 0252-2026-MTC/26 · OSIPTEL, Informe nº 086-2026-DPRC (2026) |
We list the rules we could verify. A topic with no verified rule is left out, not guessed. This is reference information, not legal advice; check the regulator link and the last-verified date.
Singapore SMS rules
| Topic | Rule | Type | Last verified |
|---|---|---|---|
| Sender | Every alphanumeric sender ID used for SMS to Singapore mobile users must be registered in the SMS Sender ID Registry (SSIR). From 31 January 2023, unregistered sender IDs are routed to the “Likely-SCAM” header. | Regulation | · IMDA, Full SMS Sender ID Registry Regime factsheet (2022-10-14) · IMDA, Factsheet on the Full SMS Sender ID Registry Regime (2022-10-14) |
We list the rules we could verify. A topic with no verified rule is left out, not guessed. This is reference information, not legal advice; check the regulator link and the last-verified date.
How this works and its limits
Each rule is restated in our own words from the regulator’s publication or an operator’s written requirement, and checked against that source before it is published. Regulation and best practice are labeled separately.
Rules change, so every row shows when we last verified it and against what. This is reference information, not legal advice: confirm with the regulator or your counsel before you rely on a rule.
Data sources and licences
Operator names, brands and codes shown here are public reference data compiled from national regulators and other public sources. Their appearance does not indicate any partnership, endorsement, agreement or connectivity between unicomam.com and the named operators. All trademarks belong to their owners. Data is provided “as is” with no warranty; verify against the official source before relying on it for routing, billing or compliance decisions.
Regulatory information is for reference only and is not legal advice; check the regulator link and the “last verified” date.
Regulatory facts are restated in our own words; each row names its regulator, the document or dataset and the date it was retrieved. Reference only; not legal advice. Credit lines used: Fonte: Anatel (dados.gov.br) · Fuente: Comisión Reguladora de Telecomunicaciones (CRT, antes IFT) México · Fuente: CRC Colombia – datos.gov.co / postdata.gov.co · Fuente: SUBTEL (www.subtel.gob.cl) · Fuente: ENACOM – Datos Abiertos · Fuente: OSIPTEL · 来源：工业和信息化部 (miit.gov.cn). Información de referencia; no constituye asesoría legal; verifique con el regulador.
Why SMS rules differ by country
Every country sets its own rules for business messaging: which sender types are allowed, whether a sender must be registered before traffic starts, which content is restricted and when promotional messages may be sent. Operators often add requirements of their own on top of the regulation.
For a platform sending to many countries, the questions are the same everywhere: can we send under our brand name, how long does registration take, and what must a message never contain. Answering them before launch avoids blocked traffic and rejected templates.
We publish each rule with its source and the date we verified it, so you can see how current it is. Where a rule is a best practice rather than a regulation, it says so.