What is an access code?

An access code, also called an access key, is a sequence of letters and/or numbers that is used to gain access into electronic systems. Access codes aren't necessarily linked to a specific user; multiple users can use the same access code for certain systems.

Access codes are used for authentication. In telecommunications, users need an access code before they can be connected to a particular region. International access codes are used for dialing international numbers, and national access codes are used for dialing domestic numbers. In digital systems, access codes are used to lock and limit access to certain systems.