GSM Phone Carriers

There's one thing most cell phone owners know: not all phones work with all cell phone carriers.

If for example, you're on the AT&T or T-Mobile network, you can't bring your device to Sprint or Verizon, and vice versa. Why? Because the four major carrier networks use two different technologies - GSM and CDMA. AT&T and T-Mobile utilize GSM, while Verizon and Sprint use CDMA.

However, just because you can't bring your GSM phone to a CDMA network doesn't mean you're stuck choosing only from the big guys. There are plenty of smaller GSM phone carriers to consider.

These lesser-known providers are called MVNOs (Mobile Virtual Network Operators). MVNOs use the same cell towers as the big four, which means you're getting solid service.

With MVNOs, you'll be able to take advantage of a lot of perks while saving a bundle on your phone bill.

But you may be asking yourself, "What's the difference between GSM and CDMA?" Well, we've got you covered with this guide to the two technologies. Once you've checked that out, you can read on below for an overview of the best GSM MVNOs.

Why Choose a MVNO?

Compared to the big four carriers - AT&T, Verizon, Sprint, and T-Mobile - these smaller carriers offer several advantages:

• Save money: With lower overhead and marketing costs, MVNOs can offer you much lower rates.
• Customized plans: The big guys' main offerings are based on unlimited data. While that sounds ideal, the average smartphone owner uses less than 3GB of data per month, not at all justifying the pricey purchase of an unlimited data plan. MVNOs allow you to pay for what you need, with no strings attached.
• No contracts or credit checks: Speaking of no strings attached, MVNOs are prepaid carriers, meaning that if you find yourself dissatisfied with the service, you can leave at any time. Better yet, you'll never have to deal with a credit check or two-year commitment.
• Keep your freedom: Did you know you can keep your phone? MVNOs welcome - and often require - bringing your own device. While those phone financing plans are tempting, you're tacking an additional $10 - $30 to your monthly bill, and that adds up to between $120 and $360 per year.

The Best AT&T MVNOs

There are plenty of tempting AT&T MVNOs in the US to take advantage of, with some featuring unique incentives including life insurance plans, excellent customer service, and more. Here are our picks:

• ROK Mobile is certainly unique, as it offers a variety of life benefits alongside its cellular plans. A few phone plans, in fact, feature telemedicine and pharmacy savings.
• Red Pocket offers data plans for not only light and medium data users, starting at far lower than industry average prices, but even many heavy data users! And GSM smartphone owners can take advantage of more data! You'll have access to unlimited texts, free unlimited international calling to over 70 countries, the ability to retain your phone number, and English, Spanish, Chinese, and Filipino customer service.

The Best T-Mobile MVNOs

T-Mobile MVNOs are also excellent, with one of these MVNOs being touted as one of the best when it comes to value. Here are what we consider to be the best picks:

• Mint Mobile shines brighter than most MVNOs because of its ability to sell you plans in bulk (by 3 months, 6 months, or 12 months), essentially saving you hundreds of dollars each year. Better yet, these plans are great for not only light data users but also medium and heavy data users as well. For instance, you can pay essentially $30 per month for a whopping 10GB of data!
• US Mobile lets you completely customize your plans. You can choose the minutes, texts, and data you'd like - minutes range between 100 and 5000, texts between 100 and unlimited, and data between 100MB and 8GB for GSM users, though if you select the Super LTE network, you'll have access to unlimited data plans.
• TPO Mobile is a feel-good MVNO, as 10 percent of your cell phone bill, as well as 25 percent of the company's profits, are donated to charities and organizations in need.

While TPO Mobile offers plentiful data amounts for light to medium data users, heavy LTE data users should search elsewhere, such as US Mobile, Mint Mobile, or ROK Mobile.

List of GSM Carriers

Recap

If you prefer GSM carriers to CDMA carriers and are tired of the pricey bills sent by T-Mobile and AT&T, then you should consider GSM MVNOs.

The options of GSM carriers are vast and low-cost, so you'll save a lot more money by switching. TPO Mobile, US Mobile, Mint Mobile, Red Pocket, and ROK Mobile are just a few of what is offered in the United States.

However, take a moment to compare cheap cell phone plans to see how much you can really save each year.