The new plans are called contract-free or “equipment installment plans,” which typically have four main costs: the price of the data plan, the cost of the device spread over monthly installments, the activation fee for each phone and the monthly cost for each phone line (also called the network-access fee).

Prices vary by carrier, and over time, the fees can shift. Once you finish paying off the cost of the phone, for example, that fee is removed from your bill and you pay a lower monthly rate for your phone bill. In some cases, you can choose to upgrade to a new device when you’ve paid off the phone.

For a flavor of the complexity of these plans, look at Verizon’s three-gigabyte contract-free plan. It costs $45 a month for the data. Each smartphone added to the plan is $20 a month. There is an equipment payment plan to pay off the smartphone over two years — the iPhone 6 costs $650, or $27 a month spread over two years. Altogether, you pay at least $92 a month. After paying off the device, you would subtract the $27 equipment charge from your monthly bill.

Contract-Free Plans

One aspect of contract-free plans that consumers should be aware of: Some can actually cost more than a two-year contract plan.

Take an individual AT&T customer who has an iPhone 6 with five gigabytes of data on a two-year contract. Over the two years, the customer would pay about $2,405 total ($200 upfront for the iPhone, $50 a month for the data plan, a $45 activation fee and $40 a month for the network access fee).

For someone who chooses the five-gigabyte plan on AT&T’s Next 18 installment plan, which spreads phone payments over two years, the customer would pay $2,465 over two years ($27.09 a month for the iPhone, a $15 activation fee, $25 a month for the network access fee and $50 a month for the data plan).