SMS compliance in India

The rules that apply to business SMS sent to numbers in India, with the source for each.

Quiet hours

Promotional SMS 10:00-21:00 by default; transactional/service 24/7.

Source: TRAI TCCCPR 2018 (as amended 2025)

Consent

Promotional SMS only to non-DND numbers or with digitally registered consent (DLT consent templates); service-implicit/explicit categories.

Source: Digital Personal Data Protection Act 2023 + DPDP Rules 2025

Opt-out

Opt-out via DND/NCPR (1909) and in-message opt-out; preferences honoured within 24h.

Source: Digital Personal Data Protection Act 2023 + DPDP Rules 2025 / regulator rules

Prohibited content

Blocked: phishing/fraud, illegal or unlicensed gambling, adult content, hate/political content (most operators), counterfeit/illegal goods, unlicensed financial offers; URL shorteners often blocked.

Source: Operator content policies / national advertising law

Data protection law

Digital Personal Data Protection Act 2023 + DPDP Rules 2025. Supervisory authority: Data Protection Board of India.

Source: Digital Personal Data Protection Act 2023 + DPDP Rules 2025

Sender ID rule

6-character header registered on DLT; numeric headers for promotional, alpha for transactional/service.

Source: Operator/regulator registration rules

Other

TRAI DLT: entity, header and template registration mandatory; URLs/APKs/call-back numbers must be whitelisted in templates.

Source: Regulator/operator rules

This summary is guidance, not legal advice. Last verified 23 October 2026.