Short Codes

A specialized virtual number designed to send and bulk SMS text messages.

What is a SMS Short Code?

A short code is multi-digit number designed to send and receive bulk SMS text messages. SMS short codes are often leased by large enterprise organizations to text market or do emergency notifications. Short codes come in two varieties: vanity and random. A vanity short code is a specific number chosen at the time of a lease. A random short code is randomly chosen at the time of a lease. Often random short codes are shared by a number of brands. Shared short codes are shared among different brands and use keywords to filter traffic to the intended brand.


What is the difference between a short code and a long code?

Short codes enable your application to send SMS at 30 messages per second versus a long code which can send 1 message per second. This high-throughput is perfect for applications that need to send SMS messages to lots of users or need to send many time sensitive messages. Additionally, based on type of application you build and the messages you're sending, a short code may be the only type of number that can support your use case. Examples of applications that are best on a short code are: < href="">SMS marketing communications, bulk text messaging and one-way notifications to users.

Where do short codes comes from?

There is a central repository of short codes created by the US mobile carriers. SMS gateway providers, such as CallFire, will lease a short code on your behalf from this registry.

How do short codes work?

SMS Gateway providers like CallFire and Clickatell have special arrangements with the major mobile carriers around the world to send two way SMS traffic. These SMS gateway providers, also known as aggregators, will send and receive SMS traffic to and from the mobile phone network's SMS Center, which are responsible for relaying those messages to the intended mobile phone. The aggregators then receive feedback from the SMS Center as to the status of the delivery of that message. This relationship between the aggregator and SMS Center allows for the transmission and reception of a large number of SMS messages to and from a short code.

What is the difference between a shared short code and a dedicated short code?

Dedicated Short Codes are yours and yours alone, while shared short codes are utilized by many companies with traffic filtered by keywords that end users lease.

How much do short code messaging cost?

Depending on which SMS gateway provider you use, U.S. to U.S. traffic, inbound and outbound, standard number or short code, the average cost of an SMS text message is $0.01 to $ 0.05 per message.

What are SMS centers (SMSC)?

A Short Message Service Center (SMSC) is responsible for handling the relay of SMS text messages for the major telecom carriers like Verizon and T-Mobile. When an SMS message is sent from a mobile phone, it will reach an SMS center first. The SMS center then forwards the SMS message towards the final mobile destination number. The main duty of an SMSC is to route SMS messages and regulate the process. If the recipient is unavailable (for example, when the mobile phone is switched off), the SMSC will store the SMS message and attempt to resend that message when the mobile device is turned on.

What is an SMS aggregator?

SMS gateway providers are often referred to as aggregators. The aggregators have multiple agreements with the large mobile network providers such as Verizon and T-Mobile to send and receive text messages through these networks' SMS Centers.

What is a direct to mobile gateway?

Direct to mobile gateways allow SMS text messages to be sent and/or received by email, from web pages or from other software applications by acquiring a Subscriber Identity Module (SIM card) . Direct-to-mobile gateways are different from SMS aggregators because they are installed on an organization's own network and connect to a local mobile network. The connection to the mobile network is made by acquiring a SIM card from the mobile operator and installing it in the gateway. Typically, direct-to-mobile gateway appliances are used for low 100's or 1000 texts per month and are not used as an enterprise solution.

How do consumers regulate short code traffic to their mobile phone?

If the recipient responds HELP or STOP to a short code, the gateway provider should stop SMS messages from being sent.

What are the output restrictions on SMS short codes?

Short codes can send up to 40 messages per second (2400 per minute). This is different than long codes that can only output one SMS per second. As such, short codes are th

What are SS7 providers?

SMS gateway providers are often referred to as SS7 providers. SS7 itself, refers to a protocol of transmitting and receiving a text message from a mobile phone to the the large carriers SMS Center. The SMS gateway providers or SS7 providers have special agreements with the large mobile networks to send and receive messages via the mobile network's SS7 protocol.

What is SS7 protocol?

SS7 refers to the protocol of transmitting and receiving text from the large mobile carriers to the mobile phone destinations. Aggregator or SMS gateway providers don't have acces to SS7 protocol so they must drive all their traffic to the large mobile networks.

Text message your entire group, instantly!


Video Tutorial: Setting up your first SMS campaign

See how easy it is to set up a campaign.  Click the icon below to watch a campaign creation tutorial video.  

SMS Video Tutorial


Enterprise grade reliability

CallFire lets you to send one or thousands of text messages instantly!  That means you get dedicated capacity, on-demand.  Do you need to get your SMS campaign to reliably notify groups at the right time? CallFire's SMS blast can do it.



Why try CallFire? 
Non-invasive e-mail alternative
Reduce infrastructure costs 
Increase time efficiency 
Keep in touch with customers more easily


Short Code Features

  • Ability to receive responses to text blasts
  • Low price, no contracts or start-up fees
  • Scalable to hundreds of thousands of messages
  • Real-time tracking and short code analytics
  • Ability to schedule for specific times
  • Exposed APIs
  • Free developer support


Coming Soon!

  • SMS polling and surveys
  • Individual short-codes
  • International capabilities


API Integration

Developers, please see our API page. CallFire exposes all its APIs so that creativity is your only limitation.


Terms & Conditions

For guidelines, please visit our Terms and Conditions Page.

Helpful Resources