# Sender ID explained - Canonical URL: https://www.broadnet.me/explained/sender-id - Language: en - Publisher: BroadNet (https://www.broadnet.me) - Markdown version of the page above, generated from the rendered page. Sender ID Topic hub Definition A sender ID is the 'from' identity a recipient sees on an A2P SMS: an alphanumeric string of up to 11 GSM-7 characters (typically a brand name), a numeric long code, or a short code. Most countries require alphanumeric sender IDs to be pre-registered with the regulator or operator before traffic will deliver. Summarised from [What is a sender ID?](https://www.broadnet.me/answers/what-is-sender-id) Last updated October 1, 2026 11 key terms On this page 1. 01Definition 2. 02How it works 3. 03Key terms 4. 04Regulations by country 5. 05Guides and further reading 6. 06Related products 7. 07Frequently asked questions [All topics explained](https://www.broadnet.me/explained) [Browse all answers](https://www.broadnet.me/answers) ## How it works 1. 1 Pick the sender type Alphanumeric IDs are one-way and suit OTPs and notifications; long codes are two-way and support replies; short codes offer the highest throughput for large campaigns. Some markets, notably the United States, do not allow alphanumeric IDs at all. [Read the full answer](https://www.broadnet.me/answers/what-is-sender-id) 2. 2 Choose a compliant ID Keep it to 11 GSM-7 characters, with no spaces in most markets, and match your brand name — generic strings like INFO, ALERT or OTP are commonly rejected. Decide up front whether it is transactional or promotional. [Read the full answer](https://www.broadnet.me/answers/how-to-register-sender-id) 3. 3 Register it in each market Submit your brand identity, the exact sender ID, the use case and sample content (plus proof of opt-in for marketing) through your aggregator. The regulator and/or operators approve, ask for clarification or reject; requirements and lead times differ by country. [Read the full answer](https://www.broadnet.me/answers/how-to-register-sender-id) 4. 4 Send consistently Operator firewalls drop unregistered sender IDs, and content that contradicts the registered classification can get an ID suspended, often within hours. Aggregator-side whitelisting stops anyone else sending under your name. [Read the full answer](https://www.broadnet.me/answers/what-is-sender-id-spoofing) ## Key terms Each term has its own answer page with the full explanation. - [What is a sender ID? A sender ID is the 'from' identity a recipient sees on an A2P SMS.](https://www.broadnet.me/answers/what-is-sender-id) - [How do I register an alphanumeric sender ID? Most regulators require alphanumeric sender IDs to be pre-registered before any A2P SMS is accepted, so registration is a prerequisite, not an option.](https://www.broadnet.me/answers/how-to-register-sender-id) - [What are SMS sender ID best practices? Register alphanumeric sender IDs in every market that requires it, keep the ID to a recognizable brand name (up to 11 GSM-7 characters), classify traffic correctly as transactional or promotional, use it consistently…](https://www.broadnet.me/answers/sms-sender-id-best-practices) - [What is sender ID spoofing? Sender ID spoofing is sending an SMS with a falsified originator — appearing as `BANK-OF-X`, `DHL`, `MyBrand` when the sender has no authorisation to use that string.](https://www.broadnet.me/answers/what-is-sender-id-spoofing) - [Short code vs long code — when to use each A short code is a 3-6 digit number leased from a country regulator/operator for high-volume A2P SMS (typically marketing campaigns, voting, donations).](https://www.broadnet.me/answers/what-is-short-code-vs-long-code) - [What is a verified sender? A verified sender is a business messaging identity that a channel has authenticated and bound to a real brand — an RCS/RBM verified agent with logo and checkmark, a verified WhatsApp Business, or a registered SMS…](https://www.broadnet.me/answers/what-is-verified-sender) - [What is A2P 10DLC? A2P 10DLC (10-digit long code) is the US carrier framework that lets businesses send application-to-person SMS from standard 10-digit local numbers, provided the brand and each campaign are registered with The…](https://www.broadnet.me/answers/what-is-a2p-10dlc) - [Sender ID registration in the UAE — the TDRA process Every alphanumeric sender ID used to send A2P SMS to UAE mobile numbers must be pre-registered with the TDRA (Telecommunications and Digital Government Regulatory Authority).](https://www.broadnet.me/answers/sender-id-registration-uae-tdra) - [Sender ID registration in Saudi Arabia — the CST process All A2P SMS to KSA mobile numbers must use a CST-registered alphanumeric sender ID.](https://www.broadnet.me/answers/sender-id-registration-ksa-cst) - [Sender ID registration in Egypt — the NTRA process Egypt's NTRA (National Telecommunications Regulatory Authority) requires all A2P SMS sender IDs to be pre-approved and all A2P traffic to terminate through NTRA-licensed local aggregators.](https://www.broadnet.me/answers/sender-id-registration-egypt-ntra) - [Sender ID registration in Jordan — the TRC process Jordan's TRC (Telecommunications Regulatory Commission) requires sender-ID pre-registration for all A2P SMS to Jordanian mobile numbers.](https://www.broadnet.me/answers/sender-id-registration-jordan-trc) ## Regulations by country Country rules that apply to this topic, from our regulations library. - [A2P SMS regulations in the United Arab Emirates](https://www.broadnet.me/regulations/uae) - [A2P SMS regulations in Saudi Arabia](https://www.broadnet.me/regulations/saudi-arabia) - [A2P SMS regulations in Egypt](https://www.broadnet.me/regulations/egypt) - [A2P SMS regulations in Jordan](https://www.broadnet.me/regulations/jordan) - [A2P SMS regulations in India](https://www.broadnet.me/regulations/india) - [SMS regulations in the United States](https://www.broadnet.me/regulations/united-states) ## Guides and further reading - [Article Sender ID registration in the GCC — a market-by-market guide](https://www.broadnet.me/blog/sender-id-registration-guide-gcc-markets) - [Article Sender ID registries worldwide — 2026 compliance map](https://www.broadnet.me/blog/sender-id-registries-worldwide-2026) - [Article UAE TDRA sender-ID registration in 2026: a practical compliance guide](https://www.broadnet.me/blog/uae-tdra-sender-id-registration-2026-guide) - [Article Saudi Arabia sender-ID rules — what the CST (formerly CITC) requires in 2026](https://www.broadnet.me/blog/saudi-citc-cst-sender-id-rules) - [Article Short code vs long code vs alphanumeric sender ID vs toll-free: choosing an SMS sender type](https://www.broadnet.me/blog/sms-sender-types-short-long-code-alphanumeric) - [Reference Verified and branded sender messaging](https://www.broadnet.me/reference/verified-and-branded-sender-messaging) - [Tool Sender ID Validator](https://www.broadnet.me/tools/sender-id-validator) Related products - [A2P SMS](https://www.broadnet.me/products/a2p-sms) - [Sender-ID registry](https://www.broadnet.me/operators/sender-id-registry) - [SMS Firewall (operators)](https://www.broadnet.me/operators/sms-firewall) ## Frequently asked questions ### How do I register an alphanumeric sender ID? Most regulators require alphanumeric sender IDs to be pre-registered before any A2P SMS is accepted, so registration is a prerequisite, not an option. The general path is: choose a compliant sender ID (up to 11 GSM-7 characters), submit your brand, use case, and sample content, then wait for regulator/operator review. Requirements and lead times differ by country — see the country guides for the exact process in each market. [Read the full answer](https://www.broadnet.me/answers/how-to-register-sender-id) ### What are SMS sender ID best practices? Register alphanumeric sender IDs in every market that requires it, keep the ID to a recognizable brand name (up to 11 GSM-7 characters), classify traffic correctly as transactional or promotional, use it consistently so customers learn to trust it, and never send content that contradicts the registered use case. A well-managed sender ID lifts trust and delivery; a mismatched one gets suspended by the operator firewall. [Read the full answer](https://www.broadnet.me/answers/sms-sender-id-best-practices) ### What is sender ID spoofing? Sender ID spoofing is sending an SMS with a falsified originator — appearing as `BANK-OF-X`, `DHL`, `MyBrand` when the sender has no authorisation to use that string. It is the SMS equivalent of email phishing, and it is the dominant vector for smishing attacks globally. The protocol weakness: GSM SMS has no end-to-end sender authentication, so the SMSC accepts whatever sender ID the originating ESME submits. [Read the full answer](https://www.broadnet.me/answers/what-is-sender-id-spoofing) ### What is a verified sender? A verified sender is a business messaging identity that a channel has authenticated and bound to a real brand — an RCS/RBM verified agent with logo and checkmark, a verified WhatsApp Business, or a registered SMS sender ID. Verification proves the message genuinely comes from the brand, closing the sender-ID spoofing gap that makes unauthenticated SMS a smishing vector. It is central to both trust and A2P monetization. [Read the full answer](https://www.broadnet.me/answers/what-is-verified-sender) ## More topics explained - [A2P SMS explained](https://www.broadnet.me/explained/a2p-sms) - [OTP verification explained](https://www.broadnet.me/explained/otp-verification) - [SMPP explained](https://www.broadnet.me/explained/smpp) - [SMS firewall explained](https://www.broadnet.me/explained/sms-firewall) - [WhatsApp Business API explained](https://www.broadnet.me/explained/whatsapp-business-api)