I have no idea that why I said contact your provider. As far as cell phone service is concerned the USA is a little backward (no offence intended it just is so).
The only way that I know-of to use one number on multiple phones/lines is with Google Voice. It can be used with cell phone lines, landlines, and VOIP lines simultaneously and in any combination, with any phone number, and in any location. All of the phones tied-to the Google Voice number ring simultaneously and the first phone to pick-up gets the call, it doesn't work as a party line. You have to be careful with your voicemail or answering machine settings on the various lines you are using because the first line to answer gets the call. I turn-off the voicemail on my secondary phones and only let my primary phone's voicemail answer, and I have it programed to pick-up after 5 rings. I didn't mention this before, but Google Voice is free.Although the above is not answering his question about;
One number on Two phones,
I do know that you can have Two Numbers on one phone. My iPhone SE (2nd gen) is capable of this.
One SIM card for one number and an “eSIM” internal device for the other number. I’m sure the more expensive iPhones also have this capability.
Take a look at which subforum this was posted in.This is a oil thread not a cell phone Q & A
Sounds like my situation i love my Samsung with the 6.4" screen but I don't find myself using my phone like many others do... I don't social media play games or watch video. I really just talk and text.. I traded in my 2nd gen se but still have my first gen se in a drawer I'm itching to pop my sim in it.I replaced both my cellphones recently and they work fine but I don't like the larger size compared to my previous 5 year old phones. Too bulky in my pocket. Thinking of getting something like a Palm Phone for day to day use. Can one number be used on 2 phones?