What is an SMS number? SMS number types explained

SMS is ubiquitous in our daily communications. Even beyond person-to-person (P2P) conversations, SMS in business-to-customer (B2C) communications has become routine—from two-factor authentication (2FA) messages to alerts and reminders and marketing campaigns.

According to G2 Crowd, SMS marketing delivers results, garnering open rates as high as 98%. With higher engagement than email, it's not surprising that texting has become a core business strategy.

But did you know that not all SMS numbers are created equal? From 10DLCs to short codes, toll-free numbers to alphanumeric sender IDs, each type of SMS number serves a unique purpose and offers distinct advantages. Understanding these differences is key to leveraging the power of SMS communication for your business.

By choosing the SMS number type that aligns with your business needs, you can ensure your messages reach your customers effectively and efficiently. Whether you're sending appointment reminders, running marketing campaigns, or facilitating two-way communication, the right SMS number type can make all the difference.

In this guide, we'll demystify SMS number types and explain how to choose the best type of number for your use case.

SMS number types

SMS numbers come in various forms, each serving a unique purpose and offering distinct advantages. Understanding these differences is key to leveraging the power of SMS communication for your business.

Here’s a quick overview of different number types. We’ll explain each one in more detail below.

10DLC (10-digit long code)

Long codes, also known as long virtual numbers, LVNs, or long numbers, are 10-digit phone numbers that can send and receive global calls, faxes, and SMS.

10DLC is a type of long code that supports A2P traffic. Some common forms of A2P SMS are appointment reminders, small-scale marketing campaigns, and bank alerts. In 2021, AT&T, Verizon, and other major U.S. carriers introduced restrictions on SMS marketing. Many carriers also provided new business registration requirements for A2P 10DLC marketing.

Use cases

Since 10DLC numbers support support two-way messages between businesses and customers, they’re a great option for B2C and P2P communications. Due to their low throughput rate (i.e., the number of messages a number is able to transmit per minute, hour, or day), long codes are best for non-marketing activities such as customer support and chat applications.

Short codes

Common short codes (CSC) are five- or six-digit phone numbers that companies and organizations can use for Multi-Media Service (MMS) or SMS. Short codes are administered by the Cellular Telecommunications and Internet Association (CTIA) via the Common Short Code program.

Use cases

These numbers have a high throughput rate and can support two-way messages, making them an optimal choice for large-scale marketing. Popular use cases include notifications, customer service, and promotional messages within the U.S. and Canada. To avoid violating SMS regulations, organizations must ask customers for an explicit opt-in to receive messages and provide information on how to opt out.

Toll-free SMS

Toll-free numbers enable businesses to host calls and exchange text messages at no cost to their customers. Toll-free numbers support two-way messages and have distinct three-digit codes (e.g., 800, 833). In the US, the Federal Communications Commission (FCC) assigns and regulates the use of toll-free numbers. Unlike short codes, toll-free numbers support both phone calls and SMS.

Use cases

Toll-free numbers allow customers to respond to an SMS alert by texting or calling the same number. They also have a higher throughput rate than long codes but a lower cost rate compared to short codes. As such, they’re commonly used in mid-scale marketing, customer support, and notifications.

Alphanumeric sender IDs

Alphanumeric sender IDs allow businesses to send one-way messages to customers. Unlike two-way messages that can send and receive SMS, customers can’t respond to one-way messages. An alphanumeric sender ID consists of a custom combination of letters (a–z, A–Z), numbers (0–9), and spaces. Companies can create IDs using brand names (e.g., TELNYX) so customers can easily identify them.

Use cases

Alphanumeric sender IDs use up to 11 characters and are ideal for non-US and Canada notifications and two-factor authentication. Not all countries support alphanumeric sender IDs, and some have pre-registration requirements. Therefore, it’s important to learn each country’s availability and process before registering with a communications provider.

Understanding the different types of SMS numbers is crucial for effective communication. Each type serves a unique purpose and offers distinct advantages depending on your needs. By choosing the right SMS number type, you can ensure your messages reach end users effectively and efficiently.

If you want more clarification, check out this clip from our SMS webinar series discussing SMS number types.

The full webinar is linked below.

Leverage SMS in your business strategies with the Telnyx SMS API

No matter your use case, it's critical to have a reliable communication partner like Telnyx to fully experience the positive impact of SMS on your business. With Telnyx's advanced SMS API, you can reach customers around the world via SMS, choosing from local and toll-free numbers, short codes, and alphanumeric sender IDs.

Our expansive inventory of numbers, coupled with our compliant global communications, allows you to choose and purchase numbers with ease, tailoring them to align perfectly with your specific business needs. The intuitive Mission Control Portal facilitates the seamless purchase and registration of numbers, ensuring a smooth transition into enhanced communication for your unique use case.

If you already have SMS numbers, our comprehensive API support and dedicated team of SMS experts allows you to seamlessly port your existing numbers and start sending SMS in just hours or days. Finally, our competitive pricing ensures the cost of sending SMS doesn't exceed the value it brings to your business.

Let Telnyx empower your business to send impactful messages that ensure effective communication and foster strong customer relationships. Begin your journey towards better business communication and customer satisfaction today.

Talk to a Telnyx SMS expert to find out how your business can leverage the power of SMS with Telnyx.

Looking for more information on SMS? Check out some of these other resources:

• Take advantage of deliverability insights from 1 billion+ messages with our 2023 Guide to SMS and MMS.
• Check out the full recording of our webinar on SMS number types.
• See how Telnyx compares to a top SMS competitor.