Feature Access Codes (FACs) are special sequences of characters that users dial from a telephone keypad to invoke features. For example, a user might press *6, following by 2023 to forward all incoming calls to extension 2023.
FACs are most often used from analog phones and from single-line digital or IP phones while users of multi-line phones select soft keys or programmable keys to invoke the same features. The same FACs are used by all phone types with certain exceptions for SIP devices; see SIP Device Support for Feature Access Codes.
FACs are enabled on all phones unless explicitly disabled by de-programming ("blanking out") the assigned characters in the Feature Access Codes form. All FACs are customizable.
See the Feature Access Codes form.
SIP devices support a subset of the feature access codes that user can dial to invoke call control features; see SIP Device Support for Feature Access Codes.
Except for SIP devices all FACs are available to all phones regardless of type. See SIP Device Support for Feature Access Codes for exceptions.
In general, FACs are dialed immediately after a phone is taken off hook. Some, such as Call Park are vaild only after initiating a transfer by softkey or feature key press or hookflash (analog phones). See the System Features section for feature-specific operations.