Does my telephone receiver have to be off the hook to use a headset?
Yes indeed, the telephone receiver should be displaced off of the instrument.
The cause being to uphold the handheld receiver up & down the hook, upon headset usage, that will happen only when the headset takes place of the handheld receiver upon the telephone. There is no change in the functioning of the phone.
Supposing you don't replace the receiver from the hook upon answering or making a call, then a phone call won't come on it. If you leave it displaced once the call is over, the receiver isn't on the hook, and thus it shall be left busy.
So as to Not need to pickup the receiver up & down the hook upon trying to use the headset, if the instrument has a feature termed as "On-Hook Dialing".
For this feature to be there, the telephone needs to either be connected to a sole headset jack, which will allow it to forego the handheld jack on the receiver. Or else the instrument needs to have a kind of headset coding feature, where the Headset is programmed to receive the telephone, there is pre-designed button right on the instrument to accept and disconnect the calls, upon making use of headset.
Go through the telephone's user guide or get in touch with the manufacturer of the telephone to check whether or not such features are available.
There are however some exceptions, these are telephones do not require you to lift up the handset. However, you must use the required Plantronics Telephone Headsets:
1) Avaya Partner Phones, you will need to use the Plantronics SP02-H amplifer
2) Avaya One-X Line 9620, 9630, Avaya 2410, 2420,
Avaya 4610sw, 4620, 4620sw, 4621sw, 4622sw, 4625sw, 4630, 4630sw,
Avaya 5410, 5420,
Avaya 5610, 5620,
Avaya 6416D+M, 6424D+M,
Avaya 8403, 8405, 8410D, 8411D, 8434, you will need Plantronics AWH-55+ or the Plantronics AWH-75