You share utilities with your roommates. Why not your phone bill?

Having roommates may already lower your cost of living: You share rent, utilities, maybe even food. If you’re managing expenses collectively, a shared cell phone bill shouldn’t be too much extra trouble.

You’ve finally moved out on your own and you’re feeling free. Free to decorate how you want, blast your stereo whenever, and — oh, right — pay your own bills.

NerdWallet has found that many young adults stay on their family’s cell phone plan because it saves money all around. If you’re not so lucky, consider setting up your own family plan with friends or roommates.

Having roommates may already lower your cost of living: You share rent, utilities, maybe even food. If you’re managing expenses collectively, a shared cell phone bill shouldn’t be too much extra trouble.

Go prepaid …

If you get some friends on board, it’s probably best to jump on a solid prepaid carrier. They’re generally cheaper than bigger carriers like Verizon and AT&T, and there’s no credit check to get service. Plus, most prepaid carriers offering family plans don’t force you to share data. Instead, they divvy up monthly data allotments into separate buckets. (Jenny might drink your milk, but at least she won’t hog your gigabytes.)

A prepaid family cell phone plan can get you significantly cheaper cell service than an individual line. For instance, a basic Cricket Wireless plan with unlimited talk and text plus 2.5GB is $40 per month. With its “group save discount,” four lines on the basic plan come out to $100 per month all together, or $25 per month, per roommate. You can save $180 a year.

… but know what you’re getting into

Many prepaid providers piggyback on bigger carriers’ networks, so the service is essentially the same. For instance, Virgin Mobile operates on Sprint’s network without restriction.

This isn’t always the case, however. When you look at prepaid carriers like Cricket, which operates on AT&T’s network, you’ll find that Cricket gets the same coverage, but its LTE data download speeds are capped below what you’d usually get on an AT&T plan.

So make sure you know whether your prepaid carrier comes with any caveats and whether you’ll get good local service on its network provider. You’ll also want to know how much data you actually need each month, as the average cell phone user usually clocks in between 2GB and 3GB. Don’t pay for more than you actually use.

Another thing to keep in mind with prepaid providers: They don’t all allow you to bring your own phone. Some, like Cricket, are compatible with most unlocked phones. Others, like Virgin, only allow you to use a handset you buy directly from the carrier. The bigger carriers all have some sort of installment plan, in which you can pay for an expensive phone over a couple of years. With prepaid carriers, you’ll have to buy your phone upfront if your current phone isn’t compatible.

If some or all of your group are in the market for a new phone, all the better. If not, you’ll have to weigh the value of purchasing new phones against the savings on your monthly bill.

For those with good credit, T-Mobile’s family plans offer a potential way out. They’re inexpensive, have separate data allotments and allow new phones to be paid in installments. Plus T-Mobile’s got some of the best data-saving features around, allowing users unlimited video and music streaming.

Don’t lose friendships over a cell phone bill

If you’re going in on a family plan with friends, make sure you set clear expectations about who’s responsible for paying the bill and when the money from everyone else is due. Your slacker roommates might be cool with a brief power outage due to a late bill, but letting their cell phone get shut off? That might be just the right amount of motivation to pay on time.

The point person whose name is on the bill might get stuck covering for a delinquent friend who doesn’t pay by the due date. So you’ll want to make sure your fellow family plan members are reliable and that they know they’re responsible for any extra charges they incur on the bill. Getting something in writing could be a good way to keep everyone honest.

Sprint used to have a “Framily” plan that allowed separate billing for different members of a family plan, but has since discontinued it. No other carriers allow separate payments, so be sure everyone remembers to pay on time.

Go ahead, float the idea to your roommates. You don’t have to be family to be on a family plan.

Stephen Layton is a staff writer at NerdWallet, a personal finance website. Email: slayton@nerdwallet.com.

This article was written by NerdWallet and was originally published by USA Today College.