Sender registration around the world: who you have to tell before you text

When your business sends a text message, the name or number it comes from is the first thing the customer sees, and the first thing a fraudster would copy. To fight scam messages ("smishing") and spam, regulators and mobile operators in more and more countries now want to know who is sending, from which sender identity, and for what purpose, before the messages flow. If you skip this step, your messages may be blocked, delayed, or shown with a warning such as "Likely Scam". This guide explains what registration usually involves and how it differs across regions. Rules change often and vary by operator: treat this as a map, and confirm current requirements with your provider and the regulator before launch.

Across very different countries, the same four things come up:

1. The business: legal name, registration number, tax ID, address, website.
2. The sender identity: a phone number, a short code, a toll-free number or an alphanumeric sender ID (a name such as "MyBank").
3. The use case: what kind of messages you will send (verification codes, notifications, marketing), sometimes with sample messages.
4. Consent and content: how people opted in, and in some countries the exact message templates.

The US has some of the most structured rules, driven by the major mobile carriers and industry guidelines from CTIA, the wireless industry association.

• 10DLC (ordinary 10-digit numbers): businesses must register their brand and each campaign (use case) with The Campaign Registry, usually through their messaging provider. Unregistered 10DLC traffic is now blocked rather than merely filtered.
• Toll-free numbers: must go through toll-free verification before sending; traffic from unverified toll-free numbers to US and Canadian numbers is blocked.
• Short codes: leased through the US Short Code Registry, with each programme reviewed by the carriers before launch.

The practical detail is in our deep dive, 10DLC without tears.

Canadian short codes are run through the Canadian Common Short Code programme, administered by the wireless industry association (CWTA), and programmes need approval from the carriers. Consent for commercial messages is governed by Canada's anti-spam legislation (CASL), which generally requires consent, sender identification and an easy way to unsubscribe. Toll-free verification also applies to toll-free texting into Canada.

Alphanumeric sender IDs are widely supported across Europe, but rules vary country by country, and some operators require pre-registration while others do not. Two trends are visible:

• Protection registries. In the UK, the Mobile Ecosystem Forum runs an SMS SenderID Protection Registry with the mobile operators: organisations register the sender names they use, and messages using those names from unauthorised senders can be blocked. Participation is voluntary.
• Mandatory registries. Ireland's regulator, ComReg, launched a mandatory SMS Sender ID Registry in 2025. From 3 July 2025, messages from unregistered sender IDs were labelled "Likely Scam", and ComReg planned to block them after a transition period.

Expect more countries to move in the same direction. Consent rules for marketing are set by national law and, in the EU, interact with the GDPR.

India runs one of the most comprehensive systems. Under TRAI's Telecom Commercial Communications Customer Preference Regulations (2018, amended since), businesses register on operators' Distributed Ledger Technology (DLT) platforms:

• the entity (called a "Principal Entity"),
• each header (the sender ID),
• each content template (the text of each message type, with placeholders for variables).

Messages are checked ("scrubbed") against the registered templates, and those that do not match are not delivered. TRAI has repeatedly tightened the rules, for example directing operators to re-verify headers and templates and block unverified ones.

In Brazil, short codes are a common route for business SMS, and support for alphanumeric sender IDs depends on the operator and typically requires pre-registration. Consent and data use fall under Brazil's data protection law (LGPD). Because requirements differ by operator and change over time, ask your provider for the current route and process for each operator you need to reach.

Several Gulf states require sender IDs to be pre-registered and approved before use, and route business SMS through licensed parties.

• Saudi Arabia: the Communications, Space and Technology Commission (CST) regulates bulk SMS; sender names are registered through a unified electronic portal, and businesses are expected to use licensed providers.
• United Arab Emirates: the TDRA regulates the sector; operators and aggregators describe separate registration of promotional and transactional senders, with promotional sender IDs carrying an "AD-" prefix.

Other countries in the region have their own regimes. See the deep dive getting messages into the Gulf.

Singapore made registration of alphanumeric sender IDs mandatory from 31 January 2023 through the SMS Sender ID Registry (SSIR), run by SGNIC, a subsidiary of the regulator IMDA. Messages from unregistered sender IDs were first labelled "Likely-SCAM" and then blocked. Organisations need a local entity number to register and must send through participating aggregators. SGNIC says applications are typically processed within two working days, and protection can take up to nine working days to start after approval.

In Nigeria, sender IDs generally need approval before use, typically arranged through providers with each mobile network. In July 2025 the Nigerian Communications Commission (NCC) began licensing international A2P messaging aggregators, to bring international business messaging into Nigeria under closer oversight. Other African markets have their own rules; check country by country.

Lead times are shown only where the registry itself publishes them.

• Start early. Treat registration as part of the project plan, not a launch-day task.
• Prepare documents once. Company registration, tax ID, website, privacy policy, opt-in evidence and sample messages are requested almost everywhere.
• Register in your own name wherever possible, so you can change provider without starting again. See evaluating a CPaaS contract.
• Keep promotional and transactional traffic separate. Many regimes treat them differently.
• Keep a register of registrations: country, sender identity, status, owner, renewal date.

The details differ, but the direction is the same almost everywhere: identified senders, declared purposes, sometimes registered content, and evidence of consent. Build that into your plan from the start, keep registrations in your own name, and confirm the current rules for every country before you send.

• 10DLC without tears: the US process in detail.
• Getting messages into the Gulf: sender IDs, licensed aggregators and the AD- prefix.