SMS Long Code vs. Short Code: Choosing the Right Option for Your Messaging Needs

As a developer building SMS functionality into your application, one of the first decisions you‘ll need to make is whether to use a long code or short code to send and receive messages. Long codes and short codes each have their own advantages and ideal use cases. In this article, we‘ll dive into the key differences between long codes and short codes, and provide guidance on how to choose the right option for your specific needs.

What are Long Codes and Short Codes?

First, let‘s define what we mean by long codes and short codes in the context of SMS:

• A long code is a standard 10-digit phone number that can send and receive SMS messages and voice calls. Long code numbers look just like a normal mobile or landline phone number.

• A short code is a special 5-6 digit phone number that is specifically meant for SMS messaging. Short codes are often used for marketing campaigns, alerts, confirmations, two-factor authentication, and other high-volume messaging use cases.

The primary difference is the length of the phone number itself. But long codes and short codes also have different capabilities, costs, and setup processes. Let‘s compare them across a few key dimensions.

Throughput

One of the biggest advantages of short codes is that they support very high throughput. A single short code can send hundreds or even thousands of messages per second. This makes them ideal for time-sensitive alerts, mass marketing campaigns, voting and polling, and other applications that need to push out huge numbers of messages simultaneously.

Long codes, on the other hand, are limited to sending one message per second. So a long code number is better suited for applications that send low to moderate volumes of messages, and do not have massive spikes in volume.

Cost

If you have budget constraints, long codes are the clear winner from an affordability standpoint. Long codes only cost around $1-2 per month per number, sometimes even less. You can get started with long codes without committing much budget.

Short codes are much pricier — generally in the range of $500-$1000 per month per short code. There are also sometimes setup fees associated with short codes. For smaller-scale applications, short codes usually aren‘t economical.

Setup Time

Another area where long codes excel is in the setup process. You can often instantly provision long code numbers through self-serve portals and APIs. There is little to no lead time required to get set up and running.

Short codes, in contrast, have a much longer setup cycle. You will need to lease the short code from the carriers, which can take 8-12 weeks. There is also an approval process to go through, where carriers vet your use case and message content. Campaigns violating carrier guidelines can be denied. For time-sensitive applications, short codes may not be feasible.

Voice Support

A key capability that long codes have, which short codes lack, is support for voice calling. Since long codes are actual phone numbers, they can make and receive voice calls and also SMS. Short codes can only send and receive SMS messages.

If your use case requires voice support, such as appointment reminders that can also be voice calls, then you will need to use a long code. Short codes are SMS-only.

User Experience and Perception

An advantage of short codes is that they provide a better user experience. Short codes are easy for users to remember, whereas a 10-digit number is harder to keep in mind. When you see a short code, it feels more official and legitimate. Short codes also have a higher brand recall.

Long codes can sometimes be perceived as spammy. While you can build trust over time, long codes don‘t have the same built-in legitimacy as short codes. Spam filters are also more likely to block long code messages. So from a pure user experience standpoint, short codes win out.

Use Cases and Recommendations

Given the different capabilities and tradeoffs between long codes and short codes, here are some general guidelines for which option to use for different scenarios:

• Marketing and promotions: For mass marketing campaigns, short codes are usually the better choice. They can handle high volume and have better deliverability and response rates. The one exception is if you are on a tight timeline or budget.

• Customer service and support: Long codes are well-suited for one-to-one customer interactions over SMS. These messages tend to be lower volume and the ability to also have a voice conversation is valuable for customer support.

• Alerts and notifications: High-priority, time-sensitive alerts are often better sent via short code for maximum reliability and throughput. But lower-priority notifications can also be sent via more affordable long codes.

• Two-factor authentication: Short codes are well-suited for 2FA because of their higher deliverability and official appearance. However, long codes can also be used for 2FA if you don‘t expect extremely high volume.

• Appointment reminders: Long codes are a good fit for appointment reminders because they allow you to send SMS reminders and also make voice calls if the SMS reminder is not confirmed by the recipient.

Conclusion

As you can see, there are significant differences between long codes and short codes for SMS messaging. Long codes are inexpensive and quick to set up, and support voice calling, but have limited throughput. Short codes allow for high-volume messaging and have strong user trust, but also high costs and long setup times.

When choosing between long codes and short codes, consider your anticipated message volume, budget, setup timeline, voice needs, and user perception. In general, short codes are best for top-priority, high-throughput use cases where cost is less of a concern. Long codes are a more affordable option for everyday messaging needs.

By weighing the different factors and matching them to your needs, you can make an informed choice between long codes and short codes. The right choice will depend on your specific use case, but this guide hopefully gave you a framework for evaluating the options.