How can Verizon tell the difference between a prepaid and contract phone?

As an example, Verizon offers the Motorola W385 with both prepaid and contract pricing. If I were to purchase a prepaid phone (which is of course less expensive), how do they prevent me from attaching to a pre-existing contract with them instead of using the prepaid service?

I’m assuming there’s some technical difference, but because they both use the same model number, it’s hard to tell which is which.

I’m not quite familiar with US cellphones, but I can tell you how it works in Denmark with GSM.

The plan you are operating on would be descided by the GSM simcard that is currently in the phone.

Phones can be either locked to a specific cell network, a specific provider or unlocked.
If it is unlocked, you can use whatever simcard in the phone that you happen to have.
If it is locked to a network, you can use it with all simcard that operate on that network, it’s quite common here that there are a few big network and other companies (MVNOs) rent themself into that network, their simcards would work with the network locked phone too.
For a provider locked phone, only that providers simcards will work.

The phone itself does not know what plan you have comitted to.

As I said, that is how it works here with GSM, things might be different elsewhere.

To my knowledge, Verizon does not require SIM cards with most phones. And even if they did, if you had a SIM card for your contract, what would prevent you from putting in the prepaid phone you just purchased?

Correct me if I’m wrong, but as far as I know, Verizon has a big database of IMEI numbers of the phones they sell. Since they use CDMA without any sort of SIM card, you need to activate through them, the phone can easily be listed there as “prepaid only” or “contract only”.

The W385 is free with new activation…I don’t know how it could be cheaper than that for a prepaid phone…

Ok, I take that back…looks like online now it’s 19.99 (i’m sure it’s more in-store, but that’s only because the store is a ripoff). How much cheaper is the prepaid version?

I think the OP is referring to phones without contract renewal – which are usually more expensive than the prepaid versions (or sometimes unlocked versions on e-bay)

Edit: Specifically W385 is $239.99 for contract plans and I believe it’s under $100 for prepaid plans.

That’s correct, which is why I stated “pre-existing” in my OP.

Wait, what? Are you talking about just getting the phone, period, with no service attached, vs buying a pre-paid version of the same phone?

Yeah, ok, I got nothing on this, either. Assuming I have correctly interpreted this clarification…

I am not familiar with Verizon’s internal systems but I used to work in cellular billing and this is basically correct. Every phone is uniquely identifiable. You would have to ask Verizon to provision the phone to the service, this isn’t something you can just do on your own. In the process Verizon will know if you try to do a switcheroo on them. What they would do in response, I don’t know.

Probably refuse to do it, is my guess.

The reason I didn’t think this was the answer was that US cellular providers have resisted keeping track of IMEI numbers for theft purposes (that is - having a record of an IMEI number and whether or not the associated phone has been stolen) because they claimed it was too much trouble. If they’re already keeping track of every IMEI number that goes through their system (Whether or not it’s been activated), that’s most of the work right there.

Not exactly “no service attached”. It’s still a Verizon locked phone purchased from Verizon. No contract extension attached – i.e. for example if you destroy your phone a couple months into your two year contract, you have to pay Verizon’s retail price for a phone.

This claim sounds like bullshit to me, because if a CDMA provider doesn’t record and track the IMEI, I don’t know how else they can identify a phone on the network.