I bet that you wonder if your old school style desk phone is compatible with a wireless headset. The short answer is yes, it is fully compatible as long as you have a corded handset (receiver) and you have your desk phone not mounted on the wall or too inclined on your desk.
The reason why the later mentioned is that there’s a device that allows to do the remote answer using a wireless headset. You wonder, what is “remote answer”? Remote answer is allowing a wireless headset user to answer the call from the distance by simply pressing the answer key on the headset or tapping it. You need to be careful at the time of getting your handset lifter, as sometimes for the design of the phone by itself the lifter will not be compatible with the desk phone, which means that in some cases the lifter will not have the proper angle to pick up the handset or in another case, the lifter will pick up the handset so high that will drop the handset off from the base.
Special mention on this topic is that handset lifters are not cordless phones compatible. As matter of fact these kind of cordless phones can be used with a corded headset that will be plugged in the side of the phone, typically a 2.5mm jack
and those headsets usually cover one ear and the phone needs to be carry with the user all the time. One compatible headset will be coming from Jabra, the Jabra Biz 1500 Mono Cisco SPA headset will be compatible with any of those cordless desk phones and with bigger issues.
A lot of people might not like the idea of having a cord dangling from their cordless desk phone, for that, Plantronics created the TR-11 adapter. This adapter allows to use any Plantronics wireless headset such as the CS540 with your cordless desk phone. The way how to setup this adapter is by using a line splitter, that can be get locally at any electronic store, plug in the cordless desk phone on one and and the TR-11 and your Plantronics wireless headset on the other end. Then you can take the wireless headset with you and if the phone rings you would be able to answer the call by tapping the headset, you still can take your cordless phone with you if need to make calls out as well or if want to see who is calling using the ID caller if you count with this service.
When choosing a handset mechanical lifter needs to match the headset as those are not as mix and match, with that being said Plantronics will be compatible just with Plantronics, Jabra with Jabra and Sennheiser with Sennheiser.
The Plantronics HL 10 Handset Lifter is the well known unit from Plantronics and 
compatible with most of the desk phones with certain exemptions which will mention down later. HL 10 lifter is fully compatible with all Plantronics wireless headsets, including CS, Savi and Voyager families.
The lifter will be attached to the desk phone and needs to be
located between the handset (receiver) and the speaker of the phone. The speaker has a built in ringer that will let the lifter know when a call is coming in and that way can tell the headset a call needs to be answered.
Note: 
If you have your old Plantronics wireless headset laying around and want to get the HL 10 lifter, make sure that you still have the Telephone interface cable. This cable is essential to make it work as it is required to plug in your Plantronics headset into the desk phone. If you lost yours or can’t find it, you can order it here.
Mitel desk phone users: The HL 10 lifter from Plantronics is not compatible with certain models of Mitel desk phones, included are the 5330, 5340 and the 5360, this due to the angle of the phone. However we have another alternative that will work for you!
The Jabra GN1000 RHL lifter is your ally here, this lifter is designed to work with any of the Jabra wireless headsets family such as the Pro 900s, Pro9400s, Engage for example.
As you can see here, the design of the lifter is on reverse when compared with the Plantronics case, so instead of picking up the handset from the top of the receiver with a lifting straight
movement, it will be picking up from the top of the receiver but with a reverse lifting movement, that allows the handset to stay at its place and avoiding to drop the handset when trying to answer a call.
And for last, but not least we have the Sennheiser HSL10II, this would be compatible with 
all the Sennheiser wireless headset systems, such as the IMPACT, Office Runner, SDW headsets. This last one has a similar design on
the action/movement as the Jabra one, so this is another alternative for Mitel users that are not compatible with the Plantronics HL10 lifter. The arm of the HSL10II does the uppercut movement and thanks to that keeps the handset on its place thanks to the design of the arm.
Most of the newer VoIP desk phones have the built in Electronic Hook Switch capability, which means that they don’t need a mechanical lifter but a special cable that take place of the lifter, making it a more intuitive, less clunkier and more reliable remote answer option. Give a call if you don’t know which is the best option for your desk phone.
