U.S. SMS Long Codes vs. Short Codes? What Is Best for My Use Case?
In the United States, there are strict regulations that dictate how businesses should interact with end users via SMS. Sending an SMS incorrectly can result in an immediate shutdown of your service, or worse fines of up to $1500 per message. The two most common ways to send SMS messages in the U.S. are using a long code or a short code as the Sender ID (a Sender ID is the “from” address of a text message). This post will assist you in understanding the differences between the 2 options and help you choose which option is best for your use case.
Long Codes
First, let’s talk about long codes (also known as Long Virtual Numbers, LVNs or long numbers). Long codes are essentially 10 digit phone numbers designated by the mobile operators for person-to-person communication. Some sample use cases include chat applications, anonymous dating applications, and customer service communications.
Other facts to know about long codes:
- Messages are limited to 1 message per second
- No setup time needed
- Many different local area codes are available for region-specific needs
Short Codes
Now, let’s talk about short codes. A short code (also known as a Common Short Code or CSC) is a 5-6 digit phone number that customers can lease, and the registry is managed by the Common Short Code Administration. Service providers can manage the short code lease on customers’ behalf and aid customers with the various short code guidelines and provisioning process. Users “opt-in” to SMS programs by texting a keyword to a short code or by entering their mobile number in a web form. Short codes support high-volume messaging and can reach many different users at once. Common use cases are:
- Alert notifications
- Two-factor authentication (often abbreviated to 2FA)
- Mobile coupons and marketing promotions
Long Code vs. Short Code Requirements
Below is a quick guide to help you navigate through the different requirements of both options:
| U.S. Long Code | U.S. Short Code | |
| Format | A 10-digit number (i.e 1-415-555-6319) | A 5-6 digit number (i.e. 54513) |
| Uses | Non-marketing, customer service, and chat applications | High-volume uses, like marketing, school/flight/appointment reminders. |
| Setup Time | Instant | Nexmo pre-approved: 1-3 business days; Dedicated: 8-12 weeks |
| Throughput | 1 mps | High throughput (30 mps +) |
| Delivery Receipts | Not supported | Supports delivery receipts |
| Max messages per day | Traffic must be bi-directional | No maximum |
| Cost | See our pricing page | |
| Regulatory | Immediate code shutdown for marketing messages. Subject to carrier filtering. | CTIA and TCPA Guidelines. |
For more information about Nexmo’s long code and short code offering, visit our virtual phone numbers and short codes pages.
