--- title: "Bulk SMS in Sri Lanka: TRCSL, Masks and Data Protection" description: "Bulk SMS Sri Lanka guide: TRCSL promotional message policy, number mask (sender ID) registration, Dialog, Mobitel, Hutch, consent, Sinhala and Tamil." canonical: "https://omnichannels.ai/blog/bulk-sms-sri-lanka-guide/" language: "en" updated: "2026-11-05" publisher: "BroadNet Technologies" brand: "OmniChannels.ai" category: "sms" primaryQuery: "bulk sms sri lanka" keywords: ["bulk sms sri lanka", "sms mask sri lanka", "trcsl promotional messages", "sender id sri lanka", "dialog mobitel hutch sms", "sinhala tamil sms unicode", "sri lanka personal data protection act sms"] published: "2026-11-05" author: "OmniChannels.ai Editorial Team" reviewer: "BroadNet Messaging Solutions Team" readingMinutes: 10 answer: "To send bulk SMS in Sri Lanka, use a provider with routes to Dialog, Mobitel and Hutch, register your alphanumeric sender (called a number mask) of up to 11 characters, send promotions only to people who agreed and include an opt-out. TRCSL's operator policy sets an 8 pm to 8 am blackout for promotions. Sinhala and Tamil text is Unicode, so a single message holds 70 characters." takeaways: ["The Telecommunications Regulatory Commission of Sri Lanka (TRCSL) is the regulator; its operator self-governance policy says promotional messages from unregistered ports or number masks will be blocked and each promotional message must carry an opt-out.", "Our regulation data records a promotional blackout from 20:00 to 08:00, which matches the table in the TRCSL policy; the policy applies it to operators' own promotions, so treat it as the safe schedule for yours too.", "Our coverage data lists Dialog Axiata (413-02), Mobitel (413-01) and Hutch (413-08) with direct routes; Airtel Lanka has been taken over by Dialog Axiata, so it no longer appears as a separate network.", "Alphanumeric sender IDs have up to 11 characters, local script is supported, requirements are set by the operators, and our published lead time is 5 to 10 business days.", "Sinhala and Tamil are Unicode (70 characters per message, 67 per part), while English fits the GSM 7-bit alphabet at 160 (153 per part)."] faq: - q: "Is bulk SMS legal in Sri Lanka?" a: "Yes, businesses send OTPs, alerts and promotions by SMS through licensed operators and their registered ports and masks. TRCSL's policy blocks promotional messages from unregistered ports or masks and expects an opt-out in each promotion. Add the data protection law, which is being phased in, and treat documented consent as the safe basis for marketing." - q: "What is a number mask in Sri Lanka?" a: "A number mask is the alphanumeric sender name that shows on the recipient's phone instead of a number. TRCSL's policy says promotional messages should be generated under a number mask that uniquely identifies the originator, and that messages from masks not registered with the operator will be blocked. Our data allows up to 11 characters." - q: "What time can I send promotional SMS in Sri Lanka?" a: "TRCSL's operator policy sets a blackout from 8.00 pm to 8.00 am for promotional messages, and our regulation data records the same window. Schedule promotions between 08:00 and 20:00 Sri Lanka time (UTC+5:30). OTPs and service alerts are not promotions and can go at any hour." - q: "Do I need consent to send promotional SMS in Sri Lanka?" a: "Treat consent as required. The TRCSL policy expects clients to warrant that messages go only to subscribers who agreed, and our regulation data calls for verifiable opt-in. Sri Lanka's Personal Data Protection Act is being brought into force in phases, so check its current status. Keep a record of when and how each number agreed." - q: "Does Sinhala or Tamil text use Unicode?" a: "Yes. Sinhala and Tamil letters are not in the GSM 7-bit alphabet, so those messages are sent as Unicode with 70 characters in a single message and 67 per part when split. English fits 160 characters. Many Sri Lankan brands send OTPs in English to stay within one part and use local script for campaigns." - q: "How long does sender ID registration take in Sri Lanka?" a: "Our published lead time for Sri Lanka is 5 to 10 business days. That is a typical range, not a promise. Operators review the application, and missing company documents can add time. Build the lead time into your launch plan and use our team to prepare and file the registration." sources: - title: "Telecommunications Regulatory Commission of Sri Lanka (TRCSL)" url: "https://www.trc.gov.lk/" - title: "TRCSL Operator Self-Governance Policy for Promotional Messages and Outbound Dialer Calls" url: "https://www.trc.gov.lk/content/files/guideline/PromotionalMessagesGuidelines.pdf" - title: "Data Protection Authority of Sri Lanka: background on the Personal Data Protection Act No. 9 of 2022" url: "https://dpa.gov.lk/Background.php" - title: "Dialog Axiata completes acquisition of Airtel Lanka, Sunday Times" url: "https://www.sundaytimes.lk/online/business/Dialog-Axiata-completes-acquisition-of-Airtel-Lanka/10-1146145" - title: "3GPP TS 23.038: Alphabets and language-specific information" url: "https://www.3gpp.org/dynareport/23038.htm" --- # Bulk SMS in Sri Lanka: TRCSL, Masks and Data Protection Canonical: https://omnichannels.ai/blog/bulk-sms-sri-lanka-guide/ Language: en Publisher: OmniChannels.ai by BroadNet Technologies This guide is for marketing, e-commerce, fintech and operations teams that want to send business SMS to mobile numbers in Sri Lanka: OTPs, delivery alerts, reminders and promotions. It explains what TRCSL's promotional message policy says, how number masks work, what the Personal Data Protection Act means for consent, which operators carry your traffic and how Sinhala and Tamil text affects message length. It is a practical overview, not legal advice; confirm requirements with Sri Lankan counsel and the operators before launch. ## What rules apply to bulk SMS in Sri Lanka? Three layers apply: the TRCSL promotional message policy, operator rules for ports and masks, and the Personal Data Protection Act No. 9 of 2022. There is no single bulk SMS statute, so you assemble the picture from each. | Layer | What it covers | Where to check | |---|---|---| | TRCSL policy on promotional messages | Registered ports and masks, opt-out, blackout period, complaints | [TRCSL policy PDF](https://www.trc.gov.lk/content/files/guideline/PromotionalMessagesGuidelines.pdf) | | Operators (Dialog, Mobitel, Hutch) | Mask registration, routes, blocking of unregistered traffic | Your provider | | Personal Data Protection Act No. 9 of 2022 | Lawful processing and consent for personal data, phased in | [dpa.gov.lk](https://dpa.gov.lk/Background.php) | Our regulation data lists TRCSL as the regulator and records that sender IDs are set up through the operators, with opt-in that must be verifiable and an opt-out handled by a STOP keyword. ## What does the TRCSL promotional message policy say? The policy is titled "Operator Self-Governance Policy for Promotional Messages and Outbound Dialer (OBD) Calls". It is written for operators, and it shapes what they require from senders on their networks. Its main points, in the text of the policy: - **Registered senders only.** Operators keep a list of ports and clients authorised to generate promotional messages, and each client warrants that its messages go only to the subscribers who agreed to receive them. - **Blocking.** Promotional messages generated by any port or number mask not registered with the operator will be blocked. - **Complaints.** Operators register complaints about unsolicited messages and investigate them. Action can include disconnecting a port or permanently blocking a number mask, after a first step of cautioning the sender. - **Opt-out.** Each promotional message must carry an option to stop receiving messages from that sender, and the blocking facility is free of charge. - **Identification.** Each promotional message should be generated under a number mask that uniquely identifies the originator. - **Blackout.** The policy's table sets a blackout from 8.00 pm to 8.00 am for promotional messages, with limits of one promotional message per day and five per week. A caution on the last point: the table sits in the section on operators' own promotions for their own products and services, so it is not drafted as a rule for third-party senders. Our regulation data records the 20:00 to 08:00 window for Sri Lanka, and following it is the sensible way to run your campaigns. Do not assume the daily and weekly limits apply to your account; ask your provider and the operators what they enforce. ## What does data protection law mean for SMS marketing? Treat documented consent as the safe basis for marketing SMS. The Personal Data Protection Act No. 9 of 2022 is Sri Lanka's data protection law, inspired by the EU's GDPR, and it applies to a phone number tied to a person. The Data Protection Authority says the Act is being brought into operation in phases, with the authority's provisions in force from July 2023 and further parts scheduled later. Check [dpa.gov.lk](https://dpa.gov.lk/Background.php) for the current commencement of the duties that apply to controllers before you design sign-up flows. A safe routine follows: 1. **Capture consent with a record:** the exact wording shown, the date and time, the channel and the number. 2. **Say who is sending and why** at sign-up, for example "Offers from Lanka Tea by SMS". 3. **Honour opt-outs immediately** and keep a suppression list across campaigns and channels. 4. **Do not buy lists.** Purchased numbers have no consent trail. For wording, our [opt-in consent generator](/tools/opt-in-consent-generator/) drafts a consent text, and the guide to [opt-in consent across channels](/blog/opt-in-consent-multichannel-campaigns/) shows how to record it. ## How does number mask registration work? Business SMS to Sri Lanka uses an alphanumeric sender of up to 11 characters, which the market calls a number mask. Our data says local script is supported and that requirements are set by the operators and confirmed at onboarding. Our published lead time is 5 to 10 business days, which is typical, not guaranteed. | Step | What to do | |---|---| | 1. Classify | Separate service and OTP traffic from promotions and plan one mask per use case | | 2. Choose names | Use your registered business or brand name; avoid names that imitate banks, operators or government bodies | | 3. Prepare documents | Business registration papers and an authorisation letter naming the mask and your provider | | 4. Submit | Your provider files with the operators and tracks each approval | | 5. Test | Send an OTP and a promotion to Dialog, Mobitel and Hutch handsets | Our [sender ID letter generator](/tools/sender-id-letter-generator/) drafts the authorisation letter, and the [Sri Lanka sender ID page](/sender-id/sri-lanka/) shows the current data. To have us prepare and file the registration, see [registrations](/services/registrations/); approval decisions stay with the operators and regulator. The background on formats is in [SMS sender ID types explained](/blog/sms-sender-id-types-explained/). ## Which operators carry SMS in Sri Lanka? Three mobile networks appear in our coverage data, each with a direct route. | Operator | MCC-MNC | |---|---| | Dialog Axiata | 413-02 | | Mobitel (SLT-Mobitel) | 413-01 | | Hutch Sri Lanka | 413-08 | Airtel Lanka, which used to be a fourth network, was acquired by Dialog Axiata, and the Sunday Times reported the share sale as completed in June 2024. Brands and number ranges can remain visible for a while, so ask your provider how Airtel-range numbers are routed today. Read delivery reports per network, not just a blended rate; our guide to [improving SMS delivery rates](/blog/sms-not-delivered-improve-delivery-rate/) shows how to diagnose a weak route. ## How should you separate OTP and promotional traffic? Keep OTPs, order alerts and other service messages on their own mask and route, and promotions on another. A promotion inside an OTP puts your login codes at risk if the route is filtered, and the blackout and opt-out expectations apply to promotions, not to codes. | Traffic | Example | Practice | |---|---|---| | Transactional | OTP, payment confirmation, delivery alert | No promotion inside; own mask; any hour | | Promotional | Sale, new product, loyalty offer | Registered mask; consented numbers only; opt-out in the message; send 08:00 to 20:00 | | Mixed | "Your parcel shipped. Get 10% off your next order" | Avoid; the offer makes it promotional | For OTP content and security, read our [OTP authentication messages guide](/blog/otp-authentication-messages-guide/). ## How do Sinhala, Tamil and English affect SMS length? English fits the GSM 7-bit alphabet, so one message holds 160 characters and each part of a longer one holds 153. Sinhala and Tamil are Unicode, so a single message holds 70 characters and each part holds 67. See [GSM-7](/glossary/gsm-7/), [UCS-2](/glossary/ucs-2/) and [concatenated SMS](/glossary/concatenated-sms/). These examples were counted against the limits (Lanka Tea is a synthetic brand). Have a native speaker review local-script copy before you use it: | Message | Encoding | Characters | Parts | |---|---|---|---| | `Your OTP is 482913. Do not share it with anyone. Lanka Tea` | GSM-7 | 58 | 1 | | `ඔබගේ OTP කේතය 482913 වේ. මෙය කිසිවෙකු සමඟ බෙදා නොගන්න.` (Sinhala) | Unicode | 54 | 1 | | `உங்கள் OTP குறியீடு 482913. இதை யாருடனும் பகிர வேண்டாம்.` (Tamil) | Unicode | 56 | 1 | | `Lanka Tea: 20% off all teas this weekend. Details: lankatea.example/p Opt out: lankatea.example/stop` | GSM-7 | 100 | 1 | Short OTPs fit one Unicode part, while a promotion in local script quickly grows into two or three parts, so write tight copy. Sinhala and Tamil vowel signs count as separate characters. Check final copy in the [SMS character counter](/tools/sms-character-counter/), and see [SMS character limits and Unicode](/blog/sms-character-limits-unicode-arabic/) for other scripts. ## When should you send? Send promotions between 08:00 and 20:00 Sri Lanka time (UTC+5:30), which keeps you outside the 8.00 pm to 8.00 am blackout in the TRCSL policy and in our regulation data. OTPs and alerts can go at any hour. The [send time planner](/tools/send-time-planner/) helps with scheduling, and [SMS marketing rules by country](/blog/sms-marketing-rules-by-country/) compares hours across markets. ## A worked example: a Colombo tea retailer "Lanka Tea" (synthetic) has 15 shops and a loyalty app, and wants OTPs, order alerts and a weekly offer. - It registers two masks, one for service messages and one for promotions, and tests both on Dialog, Mobitel and Hutch. - It collects consent in the app and at the till, storing the wording, timestamp and number, with an opt-out link in every promotion. - OTPs go in English at under 160 characters; the offer is sent in English and, as a separate version, in Sinhala and Tamil for customers who chose those languages. - The weekly offer is scheduled for mid-morning, after a check against the suppression list. - Opt-outs feed one suppression list shared with other channels. ## What are the common mistakes? - **Using an unregistered mask.** The TRCSL policy says such promotional messages will be blocked. - **No opt-out in the promotion.** The policy expects one in every promotional message. - **Sending promotions at night.** Stay outside 20:00 to 08:00. - **Underestimating Unicode.** A Sinhala or Tamil campaign can cost two or three parts per message. - **Mixing OTP and promotion on one mask.** - **Treating lead times as promises.** Plan buffer beyond 5 to 10 business days. ## How OmniChannels.ai helps OmniChannels.ai is powered by BroadNet, which has direct routes to Dialog, Mobitel and Hutch in our coverage data. We prepare and file mask registration with you, support English, Sinhala and Tamil content, and give you per-operator delivery reports, with SMPP 3.4 for high volume. For indicative list prices, see the [Sri Lanka SMS pricing page](/sms-pricing/sri-lanka/). To add a second channel, see [WhatsApp pricing for Sri Lanka](/whatsapp-pricing/sri-lanka/), then [book a demo](/demo/).