--- title: "Bulk SMS in Singapore: SSIR, DNC Registry and Sender ID" description: "Bulk SMS Singapore guide: SGNIC SMS Sender ID Registry (SSIR), the Likely-SCAM label, PDPA Do Not Call rules, operators and Chinese Unicode SMS length." canonical: "https://omnichannels.ai/blog/bulk-sms-singapore-guide/" language: "en" updated: "2026-11-06" publisher: "BroadNet Technologies" brand: "OmniChannels.ai" category: "sms" primaryQuery: "bulk sms singapore" keywords: ["bulk sms singapore", "singapore sms sender id registry", "ssir sgnic", "likely-scam sms singapore", "pdpa do not call registry sms", "singtel starhub m1 sms", "chinese sms unicode length"] published: "2026-11-06" author: "OmniChannels.ai Editorial Team" reviewer: "BroadNet Messaging Solutions Team" readingMinutes: 10 answer: "To send bulk SMS in Singapore, register your sender ID with the SGNIC SMS Sender ID Registry (SSIR) using your company's UEN, and send through a Participating Aggregator, because unregistered sender IDs are marked \"Likely-SCAM\". For promotions, follow the PDPA Do Not Call provisions: check the DNC Register or hold clear, evidenced consent, identify yourself and honour opt-outs." takeaways: ["Organisations sending SMS to Singapore numbers must register their sender IDs in the SGNIC SMS Sender ID Registry (SSIR); SGNIC says non-registered sender IDs are marked 'Likely-SCAM'.", "SGNIC says registration needs a valid Singapore UEN and typically takes about 19 calendar days; a sender ID cannot exceed 11 characters and cannot contain Chinese or Cyrillic characters.", "Only Participating Aggregators, which are SMS aggregators licensed by IMDA, can handle registered sender IDs, so the organisation registers and selects its aggregators.", "Marketing texts fall under the PDPA Do Not Call provisions: PDPC guidance sets a 21-day validity for a DNC Register check, requires consent to be clear, unambiguous and evidenced, and allows 21 days to stop messaging after an opt-out.", "Chinese and Tamil text use Unicode, so a message holds 70 characters (67 per part); English and Malay text in plain letters fits GSM-7 at 160 (153)."] faq: - q: "Do I need to register a sender ID to send SMS in Singapore?" a: "Yes, if you want your sender ID to display as registered. SGNIC states that organisations sending SMS to Singapore mobile numbers must register the alphanumeric sender IDs they use, and that non-registered sender IDs are marked 'Likely-SCAM'. Registration needs a valid UEN and goes through the SSIR with a Participating Aggregator." - q: "What does Likely-SCAM mean on an SMS in Singapore?" a: "It is a label that the registry regime applies to messages from sender IDs that are not registered. IMDA describes it as working like a spam filter. Recipients see the message grouped under a Likely-SCAM header instead of your brand name, which cuts trust and response. Registering the sender ID prevents it." - q: "How long does SSIR registration take?" a: "SGNIC says the full process typically takes about 19 calendar days, assuming complete documents and prompt payment. Our published lead time says the same. It is a typical figure, not a promise, so build it into your launch plan and prepare your UEN details and authorisation documents before you apply." - q: "Does the Do Not Call Registry apply to SMS in Singapore?" a: "Yes, for specified messages, which are messages whose purpose includes offering or promoting goods or services. Senders generally must check the DNC Register unless they hold clear and unambiguous consent that is evidenced in an accessible form. PDPC guidance sets 21 days as the validity of a register check. Transactional messages are different." - q: "How many characters fit in an SMS in Singapore?" a: "Plain English and Malay text fits the GSM-7 alphabet, so one message holds 160 characters or 153 per part when split. Chinese and Tamil text uses Unicode, which holds 70 characters or 67 per part. A single Chinese character in an English message switches the whole message to Unicode." - q: "Can I use an alphanumeric sender ID of more than 11 characters?" a: "No. SGNIC says a sender ID cannot exceed 11 characters including spaces, underscores and hyphens, cannot contain Chinese or Cyrillic characters and should not be generic. Pick a short form of your brand name that is clearly yours, and register the exact spelling you will send with." sources: - title: "SMS Sender ID Registry FAQ, SGNIC" url: "https://www.sgnic.sg/faq/sms-sender-id-registry" - title: "Overview of the SMS Sender ID Registry (SSIR), SGNIC" url: "https://www.sgnic.sg/smsregistry/overview" - title: "Full SMS Sender ID Registry Regime, IMDA" url: "https://www.imda.gov.sg/assets/ca16a175-1137-476a-bb9f-4c32e0f09c69.pdf" - title: "Do Not Call Registry and Your Business, PDPC" url: "https://www.pdpc.gov.sg/overview-of-pdpa/do-not-call-registry/business-owner/do-not-call-registry-and-your-business" - title: "Advisory Guidelines on the Do Not Call Provisions, PDPC" url: "https://www.pdpc.gov.sg/-/media/Files/PDPC/PDF-Files/Advisory-Guidelines/Advisory-Guidelines-on-the-DNC-Provisions-1-Feb-2021.pdf" - title: "3GPP TS 23.038: Alphabets and language-specific information" url: "https://www.3gpp.org/dynareport/23038.htm" --- # Bulk SMS in Singapore: SSIR, DNC Registry and Sender ID Canonical: https://omnichannels.ai/blog/bulk-sms-singapore-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 Singapore mobile numbers: OTPs, delivery alerts, reminders and promotions. It explains the SMS Sender ID Registry, the Do Not Call rules, which networks carry your traffic and how English, Chinese and Tamil text affect message length. It is a practical overview, not legal advice; confirm requirements with Singapore counsel and your provider. ## What rules apply to bulk SMS in Singapore? Two regimes apply: the SMS Sender ID Registry for how your sender ID is treated, and the Personal Data Protection Act (PDPA) Do Not Call provisions for marketing messages. The Infocomm Media Development Authority (IMDA) is the regulator in our regulation data, and the registry is run by SGNIC, which describes itself as operating the registry under a power delegated by IMDA. | Rule | What it covers | Where to check | |---|---|---| | SMS Sender ID Registry (SSIR) | Sender ID registration; 'Likely-SCAM' marking of unregistered IDs | [SGNIC](https://www.sgnic.sg/smsregistry/overview), [SSIR FAQ](https://www.sgnic.sg/faq/sms-sender-id-registry) | | PDPA Do Not Call provisions | Marketing messages, DNC Register checks, consent, identification, opt-out | [PDPC](https://www.pdpc.gov.sg/overview-of-pdpa/do-not-call-registry/business-owner/do-not-call-registry-and-your-business) | | Operators (Singtel, StarHub, M1) | Routes, filtering and delivery | Through your provider | ## Do you have to register an SMS sender ID in Singapore? Yes, if you want your messages to arrive under your own sender ID. SGNIC says organisations sending SMS to Singapore mobile numbers must register the alphanumeric sender IDs they use, and that all non-registered sender IDs are marked "Likely-SCAM". IMDA describes that label as working like a spam filter. Our regulation data agrees: registration is required through the SGNIC SMS Sender ID Registry, and the organisation registers and selects its Participating Aggregators. Earlier IMDA material also said unregistered messages could eventually be blocked. We found no official source that confirms a blocking date, so plan on the label as the current effect and check with IMDA or SGNIC, or your provider, for any change. ## How does SSIR registration work? An organisation with a Singapore UEN registers each sender ID in the registry, pays the fee, selects its Participating Aggregators and then sends through them. Details from SGNIC: - **Eligibility.** You must present a valid Singapore unique entity number (UEN). Foreign businesses can qualify through a local subsidiary or branch with a UEN. - **Format.** A sender ID cannot exceed 11 characters, including spaces, underscores and hyphens. It cannot contain Chinese or Cyrillic characters and should not be generic. - **Aggregators.** Participating Aggregators are SMS aggregators licensed by IMDA. Only they can handle registered sender IDs, and SGNIC whitelists the registered IDs with them. If you use a third-party service whose aggregator is not in the registry, your texts can still be flagged. - **Time.** The process typically takes about 19 calendar days with complete documents and prompt payment. Our published lead time says the same. - **Fees.** The fee schedule sits in the SSIR User Agreement, and payments are non-refundable. | Step | What to do | |---|---| | 1. Decide the IDs | Choose short, brand-specific IDs; one for transactional and one for promotional traffic if you want to separate them | | 2. Prepare documents | UEN details and an authorisation letter naming the sender IDs and your aggregator | | 3. Register | Submit in the SSIR and pay the fee | | 4. Select aggregators | Name the Participating Aggregators that will send for you | | 5. Test | Send an OTP and a promotion to Singtel, StarHub and M1 handsets and check the sender ID shows | Our [sender ID letter generator](/tools/sender-id-letter-generator/) drafts the authorisation letter, and the [Singapore sender ID page](/sender-id/singapore/) and [sender ID checker](/tools/sender-id-checker/) show the current position. If you want our team to prepare and file the registration with you, see [registrations](/services/registrations/); approval decisions stay with SGNIC and IMDA. For format background read [SMS sender ID types](/blog/sms-sender-id-types-explained/). ## What do the Do Not Call rules say about marketing SMS? If your text promotes goods or services, you must check the Do Not Call (DNC) Register before sending, unless you hold clear and unambiguous consent that is evidenced. PDPC guidance describes a "specified message" as one where one of the purposes is to offer or promote goods, services, land or an investment opportunity, with exclusions such as business-to-business messages and messages whose only purpose is market research. What the PDPC says in its guidance: 1. **Check the register, or hold consent.** A register check made within 21 days before you send is valid. Consent must be clear and unambiguous and recorded in written or another accessible form. Silence or failing to opt out is not consent, and verbal consent alone is not enough. 2. **Identify yourself.** Under section 44 of the PDPA, the message must include clear and accurate information identifying the sender and how to reach them, likely to be valid for at least 30 days after sending. 3. **Offer an opt-out.** After a person withdraws consent, you have 21 days to stop sending marketing messages to that number. Our regulation data adds that opt-in must be verifiable and that STOP and DNC-registry suppression apply automatically. Transactional messages such as an OTP or a delivery alert fall outside "specified messages", but only if they contain no promotion. Our [opt-in consent generator](/tools/opt-in-consent-generator/) drafts wording, and the guide to [opt-in consent across channels](/blog/opt-in-consent-multichannel-campaigns/) covers record keeping. See [DND registry](/glossary/dnd-registry/) for the definition. ## Which operators carry SMS in Singapore? Three networks appear in our coverage data, each with a direct route: | Operator | MCC-MNC | |---|---| | Singtel | 525-01 | | StarHub | 525-05 | | M1 | 525-03 | Read delivery reports per operator, not as one blended figure. Our guide to [improving SMS delivery rates](/blog/sms-not-delivered-improve-delivery-rate/) shows how to find the weak network. ## How should you separate OTP and promotional traffic? Keep OTPs and service messages on their own registered sender ID and route, and promotions on another. Banks and e-commerce brands in particular should not let a promotion share a sender ID with login codes. | Traffic | Example | Practice | |---|---|---| | Transactional | OTP, delivery update, booking confirmation | Own registered ID; no promotion inside; any hour | | Promotional | Offer, new product, loyalty message | DNC check or evidenced consent; identification; opt-out | | Mixed | "Your order shipped. Get a free item next time" | Avoid; the offer makes it a specified message | For code content and security read our [OTP authentication messages guide](/blog/otp-authentication-messages-guide/). ## How do English, Chinese and Tamil affect SMS length? Plain English and Malay fit the default GSM 7-bit alphabet, so one message holds 160 characters (153 per part when split). Chinese and Tamil are not in that alphabet, so a message with even one such character becomes Unicode and holds 70 characters (67 per part). See [GSM-7](/glossary/gsm-7/) and [concatenated SMS](/glossary/concatenated-sms/). These examples were counted against the limits (Lion City Tea is a synthetic chain): | Message | Encoding | Characters | Parts | |---|---|---|---| | `Your Lion City Tea code is 730518. Valid for 5 minutes. Do not share.` | GSM-7 | 69 | 1 | | `Lion City Tea: Your order #2087 is out for delivery today.` | GSM-7 | 58 | 1 | | `Lion City Tea: Buy 2 get 1 free this Saturday at all outlets. Details: lioncitytea.example/s Reply STOP to opt out.` | GSM-7 | 115 | 1 | | `Lion City Tea: 本周六买二送一，详情见 lioncitytea.example/s 回复 STOP 退订。` | Unicode | 60 | 1 | The Chinese promotion fits one part because Chinese is compact: 60 characters in 70. A longer Chinese message will split at 67 per part. Note that the message body may contain Chinese, even though the sender ID may not. Check final copy in the [SMS character counter](/tools/sms-character-counter/) and read [SMS character limits and Unicode](/blog/sms-character-limits-unicode-arabic/) for other scripts. ## When should you send? We have not found a regulator-published time-of-day window for promotional SMS in Singapore, and our regulation data records none. Send promotions in local daytime (Singapore Time, UTC+8), avoid late evenings and agree sending hours with your provider. OTPs and alerts can go at any hour. The [send time planner](/tools/send-time-planner/) helps schedule campaigns, and [SMS marketing rules by country](/blog/sms-marketing-rules-by-country/) compares markets. ## A worked example: a bubble tea chain "Lion City Tea" (synthetic) has 25 outlets and wants OTPs for its app, delivery alerts and a weekly offer in English and Chinese. - It registers two sender IDs in the SSIR with its UEN and selects its aggregators, planning about 19 calendar days before launch. - It collects consent in the app and at the till with the wording, timestamp and number stored, and checks the rest of the list against the DNC Register before each campaign. - OTPs and delivery alerts use plain English under 160 characters. - The English offer stays in GSM-7; the Chinese version is written as one Unicode part. - Opt-outs update one suppression list and stop marketing well inside 21 days. ## What are the common mistakes? - **Sending with an unregistered sender ID**, so recipients see "Likely-SCAM". - **Using an aggregator that is not a Participating Aggregator** for your registered IDs. - **Sender IDs with Chinese characters or longer than 11 characters.** - **Skipping the DNC check** when you have no evidenced consent. - **Mixing OTP and promotion** on one sender ID. - **Treating lead times as promises.** ## How OmniChannels.ai helps OmniChannels.ai is powered by BroadNet, which has direct routes to Singtel, StarHub and M1 in our coverage data and an office in Singapore. We prepare and file sender ID registration with you, support English and Chinese content, and give per-operator delivery reports, two-way SMS and SMPP 3.4 for high volume. For indicative list prices see the [Singapore SMS pricing page](/sms-pricing/singapore/), then [book a demo](/demo/). Small team? Our [SMS marketing guide for small businesses](/blog/sms-marketing-small-business-guide/) covers the basics.