Glossary A-Z

In case you come across an unfamiliar word!

You may come across these terms now and again so we’d like to help you get to grips with what they actually mean!




SMS sent from an Application or platform to a Phone/person. Everything sent from our platform is A2P traffic and goes over an A2P connection.


Application Programming Interface. Use our APIs to connect your application to us and send SMS and Voice messages automatically.


An Application Service Provider typically builds the system (the 'application') that enables brands to communicate with their customers via SMS, or another mobile channel.

Batch import

Importing all the information needed to send bulk SMS in an excel or CSV. file.

Bulk SMS

Sending large volumes of SMS with similar content/originator or recipient at the same time.


A letter, number, space or symbol in an SMS message.

Concatenated SMS

A message longer than 160 characters is split into a number of smaller SMS  (concatenated SMS), sent and then received as one long message on the phone.

Dedicated Short Code

A short code is owned solely by one user. All traffic received by the code is received in that account.


Delivery Receipts: confirmation of successful or failed message delivery to the phone handset.

HLR Lookup

Provides information from the Home Location Register database. This is a list of active mobile numbers, a look up can provide information on the status, operator and location of a given phone number.


A word that can be leased on Short Code, meaning all SMS beginning with that word are directed to that user.

MNP (Mobile Number Portability)

Mobile Number Portability: users can retain their mobile number when switching between one mobile operator and another. In the countries where MNP is supported, MessageBird is able to send SMS through to the appropriate operator using MNP.


Mobile Subscriber Integrated Services Digital Number: the telephone number associated with the SIM card in a mobile phone.


Also known as a ‘Long Code’ or a ‘Long Number’. This is a standard mobile telephone number that conforms to the numbering system in the relevant country and can be used for 2-way messaging.

One-way messaging

Messages that are only sent to the mobile phone (outbound only).


SMS sent from one Phone/Person to another. Two end users texting each other, rather than a system messaging a person.

Shared Short Code

A Short Code that is shared with other content providers. “Keywords” are used to differentiate incoming SMS.

Short Code

Abbreviated mobile phone number, usually 4 to 6 digits, used as a destination address for 2-way messaging programs. Short codes can be “Dedicated” or “Shared”.


Short Message Service: also known as a ‘text message’, one SMS is made up of 160 characters maximum.

Two-way messaging

Outbound messages with an inbound reply path to enable a 2-way conversation between application and person.


Extensible Markup Language: MessageBird has an XML API to connect your application to our platform.