Intro to Short Codes

SMS and MMS using a Short Code

Telephone Equipment Manufacturing | 1917


What is a Short Code?

A Short Code is a 5 or 6 digit number administered by the Common Short Code Administration for use in Application-To-Person (A2P) messaging. These numbers are called “common” because they’re provisioned across all participating mobile networks in the United States. Short Codes are built to handle messaging at scale and are typically used to reach large audiences for a range of use cases.

Short Codes are country specific and this guide is only applicable to U.S. Short Codes.

Why should I use a Short Code?

Messaging with Short Codes is an established and effective way to engage with large audiences. Unlike 10DLC (ten digit long code), where a company can register and start sending in a matter of days, Short Codes can take 6-12 weeks to provision and are often audited to ensure proper use. This scrutinous application process makes Short Codes one of the most trusted and effective channels for A2P messaging, allowing companies to reach large audiences quickly and reduce the risk of filtering at the carrier level.

Short Codes also offer the highest messaging throughput of any number-type, with delivery speeds as high as 500 MPS. Because Short Codes were built for messaging at scale, mobile carriers are expecting high volume and don’t preemptively block messages as spam.

Lastly, with a max of 6 digits, Short Codes are much easier to remember than their 10-digit counterparts in long code and Toll-Free numbers. This can improve opt-ins, open rates and engagement with your messaging campaign.

Short Code Compliance

The industry standards for Short Code Compliance are governed by the Telephone Consumer Protection Act (TCPA) as well as the industry-led CTIA. Be sure to review the regulations outlined in the TCPA and the CTIA Short Code Monitoring Handbook with your own legal counsel. You should also familiarize yourself with CTIA’s Messaging Principles and Best Practices as the carriers will look to see if they are being followed if your messages are flagged for any reason.

How It Works

Leasing a Short Code

Short Codes are provided on monthly leases and can be acquired through Voxology or directly through, should you choose to manage your own lease. Random short codes are $500/month and Vanity/Select Short Codes, ones you choose yourself, are $1,000/month.

The lease fee for a Short Code is nonrefundable, even if the code is never fully provisioned on mobile carriers. During the life of the lease, you have the exclusive right to the use of your Short Code.

If you choose to manage your own lease and migrate the Short Code to Voxology, you’ll need to provide the receipt of purchase in order to provision on our platform.

Short Code Application

After acquiring a Short Code you’ll need to submit an application ensuring your Short Code campaign is compliant. The application will include information such as: legal entity name/address, messaging use case, call to action, terms of service, customer care and opt-out methods.

Request an application from a Voxologist to get started.

Messaging Use Case

Short Codes are heavily regulated. To avoid unwanted messages over their networks, carriers want a clear understanding of what types of messages you’ll be sending. Your Short Code may be audited from time to time after provisioning to ensure compliance. The table below lists a few examples of messaging use cases for Short Codes.

Use CaseExamples
AuthenticationTwo-Factor Authentication notifications
Customer CareRespond to inbound requests, schedule appointments or notify about service availability
EngagementNotifications about community events, suggested exercises in a workout program or educational content
MarketingCustomer surveys, promotional events, abandoned cart notifications or discount codes
Public SafetyCritical messages from utility provider for service outages
OperationsWorkforce communication, shift scheduling, or delivery tracking and notifications

Call To Action

The Call To Action (CTA) for your messaging program is how your audience joins (or subscribes) and is critical for your program’s compliance. These can range from in-person sign-ups to online registration. Carriers require every short code application be submitted with a mockup of your CTA. A mockup can be of a webpage, signage or a verbal script. The mockup doesn’t need to be an exact replica of the final product as long as all the required elements are included. At a minimum, your CTA must include:

  • Name and Brief Description // “Sign up to receive account alerts from [Program Name].”
  • Message & Data Rates Apply // “Message and data rates may apply”. This exact verbiage must be used.
  • Approximate Frequency // “Message frequency varies.” “One message per week.”
  • Customer Care Contact Info // “Reply HELP for help.”
  • Opt Out Instructions // “Reply STOP to stop receiving messages.”
  • Links to Terms of Service and Privacy Policy

Be sure to review the industry standards for opt-in methods found in the CTIA Short Code Monitoring Handbook.

Terms of Service

A link to the publicly available, mobile Terms of Service for your Short Code is required for your Short Code application. While the specific requirements for the contents of your Terms and Service may vary due to the nature of your messaging use case, the minimum requirements are listed below.

  • Program Name
  • Brief description of the types of messages you’ll be sending
  • How to opt-out and opt back in
  • How to get customer support
  • State that carriers are not liable for delayed/undelivered messages
  • Message and Data rates apply
  • Link to your Privacy Policy

Please review the CTIA Short Code Monitoring Handbook and confer with your own legal counsel to ensure your Terms of Service are fully compliant.

Boilerplate Terms of Service
[Program Name]

[A brief description of the messaging program providing a clear expectation of the kind of messages you are sending.]

To cancel your subscription and opt-out of receiving any future messages from [Program Name] send “STOP” to [Short Code] at any time.  You will receive one final message confirming your decision to unsubscribe and receive no further messages. To resubscribe after canceling, either send “START” to [Short Code] or subscribe through whichever opt-in method you used initially. 

If you need customer support, please send “HELP” to [Short Code] or contact us directly at [support email address and/or TF number].

Our service providers and the mobile carriers are not liable for delayed or undelivered messages. Message and Data rates may apply for any messages sent or received as part of this program. [Approximate message frequency].

Review our Privacy Policy here: [Link to Privacy Policy]

Keyword Support / Opt-In, Opt-Out, Customer Care

It is required that all Short Codes are configured to respond to messages containing certain keywords. The responses for these keywords must be included in your Short Code application. At a minimum, your Short Code should support keywords to opt-in, opt-out and receive customer care information.

FunctionKeywordsExample Response
Opt-InSTART“You have subscribed to [Program Name] account alerts. Message frequency varies. Message and data rates may apply. Reply HELP for help. Reply STOP to stop.”
Opt-OutSTOP, CANCEL, UNSUBSCRIBE, END, QUIT“You have opted-out of [Program Name] account alerts and will receive no further messages. Reply START to opt-in.”
Customer CareHELP[Program Name] account alerts. Call 888-123-4567 for customer support or more information. Reply STOP to stop.”

Please review the CTIA Short Code Monitoring Handbook for requirements specific to your messaging use case for Opt-In, Opt-Out and Customer Care responses.


During the provision process, your Short Code may be tested by the carriers. During testing your Short Code will be expected to respond to the keywords with the responses listed in your application.

Take a look at Voxology’s Getting Started Guide for Programmable SMS to learn how to configure an auto-responses for your Short Code.

Short Code Fee Structure

There are various one time, recurring, and usage-based fees associated with registering and using a Short Code for messaging. The fees outlined below are set by your messaging provider, their vendors and the mobile carriers. Prices were last updated on April 13, 2023 and are subject to change at any time.

One Time Fees

Setup Fees

There are a variety of setup fees associated with provisioning a short code on a messaging network depending on what features you require and what provider you choose. These fees can vary so be sure to inquire with your provider about the cost of setting up your short code.

Recurring Fees

Lease Fee

The lease fees below are the list rates assuming you manage your own lease and are often billed quarterly. Lease fees can be more expensive if a third-party vendor manages your lease.

Short Code TypeMonthly Fee

Usage Fees

Carrier Fees

Carrier Fees are charged by the mobile carriers per message part sent or received in addition to any messaging rates charged by your messaging provider.

CarrierSMS InboundSMS OutboundMMS InboundMMS Outbound
US Cellular$0.00$0.0035$0.00$0.01

Messaging Fees

Fees charged by the messaging provider for each SMS or MMS message part sent and received.

See Voxology’s Short Code SMS and MMS rates on our pricing page.

Getting Started

To get started, Speak with a Voxologist or register now in the Voxology Portal.