A dedicated phone number that enables a business to receive SMS text messages, voice and fax from anywhere in the world.

What is a long code?

SMS long codes refer to a standard 10-digit dedicated phone number that enables a business to receive SMS text messages, voice and fax from anywhere in the world. Unlike short codes, which are generally shared across many brands, long codes allow businesses to have their own dedicated phone number to receive and transmit SMS text messages. These long codes are intended for person-to-person communication, similar to the way cellphone texting plans operate.

How do long 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 networks' SMS centers, or SMSCs, which are responsible for relaying those messages to the intended mobile phone. The aggregators then receive feedback from the SMSC as to the status of the delivery of that message. This relationship between the aggregator and SMSC allows for the transmission and reception of a large number of SMS messages to and from a long code.

What are SMS centers (SMSCs)?

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 SMSC first. The SMSC then forwards the SMS message towards the destination. 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. It will forward the SMS message when the recipient is available.

Most of the major carriers run their own SMSCs. You must know the address of the wireless network operator's SMSC in order to use SMS messaging with your mobile phone. Typically, an SMSC address is an ordinary phone number in the international format. A mobile phone should have a menu option that can be used to configure the SMSC address. Normally, the SMSC address is preset in the SIM card by the wireless network operator, which means you do not need to make any changes to it.

What are the key differences between short codes and long codes?

There are a number of important factors in choosing between long codes and short codes. Long codes are standard phone numbers, such as 1 (213) 221-2289. Short codes are the much smaller, five- to six-digit numbers that you typically see used in marketing and promotions: For instance, "Text A to 55444 to get a discount on your next order." The key distinction between the two is that long codes are intended as a person-to-person communication tool, whereas short codes allow for the bulk messaging that is typical of marketing and emergency notification campaigns. A business can receive text messages to their long code, but a high volume of SMS to or from a single phone number may trigger carriers' spam filters and blacklist your long code.

Here are some important considerations to keep in mind:

Pricing. Long codes can be significantly less expensive than short codes. A standard long code usually costs between 1 to 2 dollars and between 2 to 5 cents to transmit text messages. Short code pricing varies depending on whether it is a shared code, where a number of brands share the number, or a unique dedicated short code. Shared short codes allow businesses to purchase a keyword, which act as a reception mechanism for a business's SMS text traffic. These keywords range from 15 to 30 dollars a month. Purchasing a unique short code for a business or app, however, can be quite costly. The average price for a random short code is $3,000 per month and $4,500 for a vanity short code. Long codes are significantly more affordable than short codes because they are not intended to transmit a large volume of SMS text messages.

Application. Long codes have content restrictions that allow carriers to block traffic. Long codes are strictly intended for person-to-person interaction. Significant traffic to a long code will risk having the application blocked. Short codes, on the other hand, are open to high-volume traffic applications.
Features. Long codes have the same abilities as any 10-digit number — send and receive SMS text messages, fax and voice. Short codes, on the other hand, do not have the ability to send or receive voice or fax. Instead, they are used as a tool to send and receive high-volume text messages.
Output Restrictions. Long codes are restricted by the carriers to one message per second (60 messages per minute) per originating phone number. This cannot be increased. Short codes can send up to 40 messages per second (2,400 per minute). Duplicate messages sent within one minute will also be filtered, for both long codes and short codes. A "duplicate message" is defined as the same to, from and message/body.

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' SMSCs.

What is a direct-to-mobile gateway?

Direct-to-mobile gateways allow SMS text messages to be sent and/or received by email, from webpages 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. Direct-to-mobile gateway appliances are usually used when the texts per month number in the low hundreds or low thousands, and are not used as an enterprise solution.

What are SS7 providers?

SMS gateway providers are often referred to as SS7 providers. SS7 refers to a protocol of transmitting and receiving a text message from a mobile phone to the large carriers' SMSCs. The SMS gateway providers, or SS7 providers, have special agreements with the large mobile networks to send and receive messages via the mobile networks' 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 access to SS7 protocol, so they must drive all their traffic to the large mobile networks.

Can toll-free numbers be used as a long code to send or receive SMS text messages?

Toll-free numbers are not connected to the SMS system in the U.S. or Canada, so there is no current way to enable a toll-free number for SMS. Carriers that receive an SMS message destined for a toll-free number will not deliver it, as they have no mechanism for routing such messages.