You and everyone else have been empowered for many years to keep your phone number regardless of what provider you move to. This is a right that is mostly misunderstood in the US that we'd like to help you undestand.
About a decade ago the US government told telecoms they could no longer lock us in to their service by holding the number we use hostage. This, like a lot of recent telecom regulation, started with wireless numbers.
When you transfer your number between providers, this is called a "port" and the process is heavily regulated. It begins with a port request. You find a new provider, of which Phone Janitor is one option, and you get them to start this request. Not all providers offer this service, but most do. You have to give a bunch of information and essentially prove you are the current holder of the number, but aside from the paperwork the process is as painless as working with telcos gets.
After the port request is made, the "losing provider" that currently services the number tells your new company either yes or no. Accept or reject. They have a very limited amount of time to do so. Some providers require you to "unlock" your account for a transfer beforehand, and some will charge a small fee to do so. The regulations here are complicated, so we don't get into them, but sometimes this is perfectly legal and sometimes it is not. Chances are you won't run into a case where it is illegal.
If rejected, you can resubmit, but if it's a fraudulent request, the FCC can fine your new provider for requesting too much, so they will typically want you to be very sure about it the second time. If accepted, the providers negotiate a time for when the "port" will go through. This is typically an exact time, but it's not a perfect handoff either. The question we always get is "how long" will this transfer take?
I've worked with a lot of providers, and I've done this for many years before we started Phone Janitor. Wireless providers are typically done in hours or less, but can take up to a few business days. If a landline provider is involved, they're given over a month of time. Typically this happens within two weeks, and I've seen it happen in less than 5, but it is rare. This is just one of the limitations of telecoms, one that we like to work around where we can.
For the most part, a port between any providers is some initial leg work for you and your new provider, but after the process is started, it's a waiting game. Frustrating as it may be, this is a great privilege and you should try to hold onto your number because of this opportunity. You never have to tell all your contacts you got a new number ever again. If you start getting a lot of unwanted calls, Phone Janitor specializes in handling that kind of case. Now is the best time ever to keep your number and not let it or the telecom providers hold you back.