XM is an MVNO, you can't change it and its not worth the price to get it.
If someone ported or transferred their landline phone number to XM or another carrier, then that number and associated name may still be in the databases that many landline companies use in their caller id functions.
That is my best guess, and I am sticking to it.
We have had XM service for about 1.5 years. I asked same thing but only answer I got was since a new service they hadn't set it up yet to allow for that. Still waiting for this option to be allowed.
I just moved 2 lines from Verizon wireless to Xfinity Mobile. Each line had their own caller ID. Once on XM, both lines were assigned the same caller ID. I spoke with tech support today and was told that they could not change the caller ID to the same name as they were on Verizon. Instead of assigning the correct name to the line, all they could do is to assign "wireless caller" to the line and that would take 72 hours. It seems that the caller ID info gets mixed up in the process of porting phone numbers from Verizon to Xfinity Mobile.
We had ATT before we switched. Would think after 1.5 years on their system would be able to 'fix' this issue.
I was sold on transfering from Verizon to Xfinity on supposedly saving about $54/month. Instead of being billed less, I am now billed the same $68/month and NO incoming or outgoing Name Caller ID which is ridiculous and should have been made clear when I switched. Looks like I will be going back to Verizon or other Samsung Ultra20 (whatever) model carrier is available that doesn't pull a bait and switch.
I had talked to customer service and was originally told that wasn't available because comcast mobile was still brand new. Have attempted to contact them again (don't use their ask xfinity cause it has not idea what asking) and was told to call them vs chatting online. So guess will either go into local store or call them.
They actually did have it at one time where could chat with a live person online vs calling--- was very nice. Wish that was still available.
UPDATE: attempted to call 800 support. Person said not option they could do, would ask tech support to help me--- then my call was disconnected.
Did find another post within last month (same question) and they were told to use this link--- actually chatting online w/ somone. https://www.xfinity.com/xfinityassistant/