The Business Guide to SMS Sender ID

“How do I set my SMS Sender ID and what are the rules?”

Whether you are sending transactional alerts, marketing messages, or secure one-time passwords, the SMS Sender ID plays a vital role in message recognition, trust, and deliverability. This guide explains what an SMS Sender ID is, how it works, and how to configure it using MyLINK Engage or MyLINK SMS API.

What is an SMS Sender ID?

The SMS Sender ID is the name or number that appears on your recipient’s phone to show who sent the message. It could be your company name (e.g., LINK) or a phone number (e.g., +447000000123).

There are two primary types of Sender IDs:

• Alphanumeric (letters and numbers, e.g., “LINKMobility”) – up to 11 characters

• Numeric (only numbers, e.g., a mobile number or short code) – up to 15 digits

The sender ID is also called the originator or from address.

SMS Sender ID Rules by Region

Sender ID regulations vary across regions and mobile networks. While some markets allow full flexibility to use custom alphanumeric sender IDs, others may limit usage to numeric formats or require official registration before you can send messages.

In certain areas, sender IDs must go through a registration process with local carriers or regulatory bodies. This can involve documentation, verification steps, and waiting periods before your chosen sender name is approved for use.

Some regions also enforce strict filtering to prevent fraud. This includes blocking specific high-risk terms (such as financial or authentication-related phrases) from being used as sender IDs, even if they have not been formally registered.

To ensure compliance and avoid delivery issues, it is important to adapt your sender ID strategy to each destination. With MyLINK Engage, LINK Mobility helps you manage these requirements - automating registration workflows and optimizing sender ID configurations for every market.

Can Recipients Reply to an SMS Sender ID?

Only numeric sender IDs support replies. If you use an alphanumeric name (e.g., MyShop), recipients will not be able to respond directly.

For two-way SMS interactions - such as surveys, confirmations, or support - use a numeric long code, short code, or virtual number enabled through MyLINK Engage.

Are Spaces, Symbols, or Unicode Allowed?

No. Sender IDs must follow GSM standards:

• No spaces

• No special characters or symbols

• No emojis or Unicode

• Only Latin alphabet (A–Z, a–z) and digits (0–9)

Examples:

• ✅ Valid: Shop24, DealSMS1

• ❌ Invalid: Shop 24, Deal@SMS, 😊Shop

Can Sender IDs be Spoofed?

Yes - if not protected. Unfortunately, in some countries where sender ID control is open, fraudsters can fake sender IDs in smishing attacks. A spoofed message may even appear in a recipient’s existing conversation thread, making it dangerously convincing.

To combat this, many countries and carriers are tightening sender ID policies. MyLINK Engage helps protect against spoofing by enforcing registered and verified sender IDs where required.

Restricted Sender IDs and Local Filtering Rules

To combat SMS fraud and spoofing, many mobile operators around the world have implemented restrictions on generic or high-risk sender IDs - terms often misused in smishing attacks, such as “Alert,” “OTP,” “Bank,” or “Payment.”

For example, in 2023, UK operators like BT/EE began blocking messages using certain generic terms as sender IDs. Similar restrictions are increasingly common in other markets.

To help you stay compliant and avoid delivery issues, MyLINK Engage and MyLINK SMS API automatically flag sender IDs that may be blocked in specific countries or by local carriers.

Can I Change the Sender ID from my Phone?

No. If you are sending from a regular mobile (P2P), the sender ID will always display your mobile number. To customize it, you must use a business-grade SMS platform like MyLINK Engage or integrate through the MyLINK SMS API.

How to set Your Sender ID with LINK Mobility

You can set and manage your SMS Sender ID in two ways:

1. MyLINK Engage (Web-Based Platform)

• Easy setup of alphanumeric or numeric sender IDs

• Manage replies with virtual numbers or long codes

• Schedule or automate messaging flows with verified IDs

2. MyLINK SMS API

• Set sender_id parameter in your API requests

• Use dynamic sender IDs per message or per campaign

• Integrate with your existing CRM or software stack

Why do Some Countries Restrict Sender IDs?

To prevent fraud. Freeform sender IDs can be misused to impersonate brands, banks, or government entities. Fraudsters use this to launch smishing attacks, tricking users into giving up passwords or financial information.

Regulations are tightening to restore trust in SMS as a secure communication channel. At LINK Mobility, we actively monitor sender ID policies and support you in staying compliant.

What you Need to Know About SMS Sender ID

If you are new to SMS Sender IDs—or need a quick refresher—here is a summary of the key points to keep in mind when planning your messaging campaigns across different markets:

Need Help Configuring Your SMS Sender ID?

Setting up and managing your SMS Sender ID correctly is important for ensuring message deliverability, compliance, and customer trust - especially when operating across multiple countries with different regulations.

At LINK Mobility, we support businesses throughout the world with the tools and expertise needed to configure sender IDs for all use cases, whether you are sending transactional notifications, marketing campaigns, or time-sensitive authentication codes.

With MyLINK Engage, you can easily manage sender ID settings at the campaign level. If you prefer to integrate directly, MyLINK SMS API gives you full control to define sender IDs dynamically - ensuring flexibility while staying aligned with local regulations.

Our team stays up to date with international rules and carrier restrictions, helping you avoid blocked messages, improve delivery rates, and maintain a professional sender identity.