Comparing wireless plans can be a challenge because you're typically dealing with a moving target. The big four carriers AT&T (T -1.40%), Verizon (VZ -1.61%), T-Mobile (TMUS -2.58%), and Sprint (S) change their deals and specials fairly often. 

Sprint, which is trying to merge with T-Mobile, has generally been the cheapest carrier, but its deals can be confusing. Some only last for a limited time while others lock you into keeping an older phone or come with restrictions you may not want.

The same thing happens at various times from all four major carriers, which makes it hard for consumers to know where to turn. It's possible, though, to not use one of the big four. You can instead opt for a second-tier carrier offering prepaid wireless plans that can save you a lot of money. There are, however, some catches and making the switch may not be right for everyone.

A person holding a smartphone while looking at it.

You don't have to use one of the major carriers. Image source: Getty Images.

Prepaid vs. postpaid

The big four wireless carriers generally offer postpaid service. That means you sign up for a plan and pay your bill at the end of the month -- sort of the way you generally pay for cable or electricity. The smaller carriers, some of which are owned by AT&T, Verizon, T-Mobile, and Sprint, offer prepaid plans, meaning that you pay for the month before you can use your phone.

Prepaid plans are often cheaper, at least in the base price, than what the major players offer, but there are a few things to watch out for:

  • Data limits: Some plans come with a certain amount of data included and then you pay if you need more. Others offer some data at a 4G/high-speed rate and then slow you down if you go over.
  • Lack of phone options: You may not be able to use some popular smartphone models with some services.
  • No ability to spread out phone payments: Secondary prepaid carriers generally don't lease phones or sell them on installment plans.
  • Coverage gaps: These carriers lease network access from one of the big four carriers. In some cases, they look to connect over Wi-Fi first, which can lead to occasional wonky connectivity issues.
  • Poor customer service: Yes, service can be even worse than AT&T and Verizon because, in many cases, it's mostly self-help and it can be hard to get a human on the phone.

Going with a prepaid plan makes sense if you're not a major data user and you're willing to use an older or off-brand phone. That's not for everyone, and if your phone is part of your livelihood, it may not be smart to pinch pennies in this area.

Should you drop your major carrier?

For most individuals, the savings may not be worth the hassle. If you have a family with a few phones, however, saving $20-$30 per person per month starts to add up fast.

Start by looking at your monthly phone bill. Does your family need unlimited data? Is one person or a few people showing different usage patterns than others?

Once you understand how you use your phones, consider your options. There are a lot of prepaid carriers, with some focusing mostly on offering a low price while others provide a lot of choices. Look through the options and examine partners for each prepaid company.

If, for example, you're a happy T-Mobile customer, you might consider switching to Metro, a prepaid brand it owns. If you're unhappy with your current service, you may consider a prepaid player partnered with a different major carrier.

The savings for switching can be big if you make sacrifices. Giving up unlimited data will save you money -- assuming you're not going over your limits with your new carrier. Your options are very broad here, so do some homework and, in many cases, switching will save you money.