Long code: definition and how it works
Published and updated
A long code is a standard full-length phone number, such as a ten-digit United States number, used as the sender of SMS.
How it works
Long code is the industry's name for an ordinary phone number when it is used for messaging. The name distinguishes it from a short code, which is five or six digits. In the United States a long code has ten digits, hence the term 10DLC for the registered A2P channel built on it. In other countries the length varies with the national numbering plan, but the idea is the same: a number a person could dial.
Long codes are the default sender type for most SMS traffic. They are cheap to rent from cloud providers, usually around a dollar a month each, they support two-way messaging, and they exist in almost every country. Their limits are throughput and trust. A cloud provider's long code sends at a capped rate per second, and carriers apply spam filtering to it, which is why the United States moved A2P long code traffic into 10DLC registration.
A long code can be virtual or real. A virtual long code is a number a provider allocates from its inventory and routes over its carrier connections; nobody holds a SIM for it. A real long code is a mobile number attached to a SIM card in a phone. To the recipient they look identical. To the network they are different: the virtual number is A2P infrastructure, the SIM number is a subscriber line.
Long codes are the right choice when recipients need to reply or call back, when you send in more than one country, or when volume is modest.
How this applies with textbee
The number on the SIM in your textbee device is a real long code. It sends and receives like any phone number, in whatever country the SIM is from, without renting a virtual number from a provider.
Related terms
- Short code: A short code is a five or six digit phone number leased for high-volume application-to-person SMS within a single country.
- Virtual number: A virtual number is a phone number not tied to a SIM or a physical line, allocated from a provider's inventory and routed over the internet to whatever application or device the owner configures.
- 10DLC: 10DLC (ten-digit long code) is the United States system for sending application-to-person SMS from ordinary ten-digit phone numbers, with the sending brand and its campaign registered and verified in advance.
- Sender ID: The sender ID is what the recipient sees in the from field of a text message: a phone number, a short code, or a registered brand name.