2.2. Function Keys & Codes

You can alter the configuration of the freely assignable function keys via ncontrol.nfon.net under Configurations - Function Keys. Alteration is also possible via the administration portal. Long names will be displayed in abbreviation.

Yealink T52S, T54S

You can save up to 12 (T52S) or 16 function keys (T54S) on three levels on your telephone.

Additional function keys can be configured via the EXP50 expansion module.

Yealink T41P, T42G, T46G

You can save up to 15 or 27 function keys (T46G) on three levels on your telephone.

Yealink T48G

You can alter and save up to 29 functions on your display. All keys will be displayed at once when pressing the DSS key on your display. Further freely assignable function keys can be configured via the extension module EXP40 (only available for T46G and T48G).


Extension / telephone number

You can add any extension or telephone number to the busy lamp field.

  • You can start a call by pressing the respective busy lamp key. If an internal extension is programmed, you can see whether that extension is currently busy:
    • If the LED next to the key flashes, the party receives a call.
    • If the LED is consistently lit, the party has answered a call and is currently busy.
    • If the LED next to the respective key flashes, you can take the call by pressing the respective key next to the flashing LED.


You can add any extension in the PBX system and then use this function key to directly communicate with this extension through the intercom. The other party must have the intercom activated on their device. Intercom refers to a conventional intercom system (similar to walkie-talkies) directly connecting you to the other party’s speaker by pressing the assigned function key.

Additional functions via * codes

Entering various codes (as listed on the following page) allows you to additionally program functions such as call transfer to the keys.To do so, simply enter the code with the desired number in the entry field.

Control codes allow direct access to the telephone system’s functions. The following codes apply:

**## Restart devices, only for snom devices!
#+n Use outside line "n" to call the telephone number ("n" replaces the “0” otherwise required to access an outside line)
*1 Start and end voice recording (if this function is enabled for the extension)
*10+profile number Activation of the call forwarding profile
*11+TN Permanent call forwarding to telephone number (TN)
**11 Cancel permanent call forwarding
*12+TN If not available, forward to telephone number (TN)
**12 Cancel call forwarding if no answer
*13+TN If busy, forward call to telephone number (TN)
**13 Cancel call forwarding if busy
*14+TN If not registered, forward to telephone number (TN)
**14 Cancel forward if unregistered
*2+Speed dial Directly dial the extension/telephone number via speed dial
*3 Pick up the last call ringing in the pick-up groupe
*3+EXT Pick up call coming in to the extension (EXT)
*490 Activate call waiting
**490 Deactivate call waiting
If busy, automatic callback activated
If busy, automatic callback deactivated
‌*55 ‌Specify primary device within a premium extension (Premium Package)
‌*72+nnnn1 ‌Call skill service nnnn
‌*73+nnnn1 ‌Call eFax additional costs will occur
‌*74+nnnn1 ‌Call time control nnnn
‌*75+nnnn1 ‌Call group nnnn
‌*76+nnnn1 ‌Call announcement nnnn
‌*77+nnnn1 ‌Call queue nnnn
‌*78+nnnn1 ‌Call conference service nnnn

*791            Access voice mail for this extension with password

*791158       Access voice mail for extension 158, with the password for 158!

*11*791       Transfer your calls to your voice mail

*11*791158  Transfer your calls to the voice mail of the extension 158

‌*792  ‌Access voice mail entering extension number, e.g. for remote enquiry
‌*80 ‌Activate intercom
‌**80 ‌Deactivate intercom
‌*80+NST ‌Intercom to extension (EXT)
‌*84+nnnn1 ‌Become member of the queue with service ID nnnn
‌**84+nnnn1 ‌Leave queue with service ID nnnn
‌*85 ‌Echo extension
‌*86 ‌Block caller ID (CLIR)
‌*860 ‌Show main number as telephone number
‌**86 ‌Show telephone number incl.direct dial (CLIP)
‌*87 ‌Subscribe to Skill-set
‌**87 ‌Unsubscribe to Skill-set
‌*9+Project Number ‌Define a project number for outbound calls. (Note: The project number is only valid for the very next outbound call)
‌Function codes for conference rooms during an active conference.  
‌Activate or deactivate mute.
‌Express your needs.
Activate or deactivate mute of all participant.
‌Lock the conference.
1) nnnn is the four digit Service ID with leading zeros (0). For example, in a callgroup, IVR, eFax, etc. This means: is the Service ID "1", "0001" must be entered when entering the function code.