Everything you need to know about the AT&T Unlimited plan

A complete breakdown of the AT&T Unlimited plan so you know exactly what you get if you switch.

In the United States, there are a lot of companies that can get you and your phone online, but most people use one of the four biggest: AT&T, Sprint, T-Mobile and Verizon. Choosing between them can be difficult. Your first priority should be what service works best in the places you spend your time. It's not worth saving $10 a month if the service is bad. Once you have that sorted, you can look at what each company has to offer and the prices they charge for it.

More: Which unlimited plan should you buy?

Let's take a look at the AT&T Unlimited plan to see what they can give you and what it will cost.

Note: The details of this plan are current as of February 20, 2017.

AT&T Unlimited plan details

• Unlimited talk, text, and data
• Unlimited talk and text to Canada and Mexico
• Advanced messaging between compatible phones on the AT&T network
• Unlimited talk, text, and data in Canada and Mexico with free Roam North America Feature (if more than 50% of use is outside the U.S. the plan can be terminated)
• Unlimited music and video streaming with optional Stream Saver for less data use

AT&T's definition of Unlimited Data means that after you use 22 GB in a single month, your service can be slowed down if you're in a congested area. You'll hear the word throttled used here but you need to know that it's only a temporary deprioritization of your data connection when you're in a busy area. It may not happen at all depending on how many other customers are using the same towers.

Advanced Messaging features are only between two capable phones using the AT&T network in standard domestic coverage areas. A limit of 10MB is applied for any attachments. Standard text messaging has a 1MB limit for attachments.

Users who activate the free Roam North America feature need to use their phone in the domestic coverage area (U.S, Puerto Rico, and U.S. Virgin islands) the majority of the time. If 50% or more of your use in a billing period is outside of domestic coverage, your service can be terminated.

AT&T makes it clear up-front about what devices are eligible and exactly how you can use the service. Clarity is great and we appreciate it.

You can use any phone that's compatible with AT&T's network. If you bring your own phone you'll pay a $25 one-time activation fee which is added to your first bill. You can also finance a phone through AT&T and the monthly cost will vary depending on which phone you choose. The AT&T Unlimited plan does not include tax and all the other assorted fees in the price.

This plan does not include mobile hotspots (except connected cars), Wireless Home Phone, Wireless Home Phone and Internet, laptops, Timex devices, and ZTE Spro 2 projectors. Users with any of those devices should contact an AT&T representative.

Additional lines can be added to an AT&T Unlimited plan. Every line has the same benefits outlined above and the $25 dollar fee applies to each. Here is a pricing breakdown.

• One line of service on an AT&T Unlimited plan is $100
• Two lines of service for $140
• Three lines of service for $180
• Four lines is $180 (The 4th device is free via a $40 bill credit on or after the second month)

AT&T Unlimited Plan add-ons

You can add a tablet or connected car to your AT&T Unlimited plan for the standard $40 monthly fee or through the AT&T 1GB Tablet plan. This plan offers 1GB of data for your tablet for $10 per month, with overages at $15 per Gigabyte. You can add a wearable (Timex wearables are not eligible) to your plan for $10 a month. You can also add a feature phone or messaging phone to your account for $25 per month.

Secondary perks

AT&T offers a plethora of services and apps to use them. Services include AT&T Drive Mode, AT&T Tablet messaging, AT&T Locker and more. You'll find these apps and plenty more in the App Store.

Last but not least, AT&T also offers services tailored to business owners. Business Messenger, Global IP Client and more make it easier to merge your physical office with your virtual office. You'll find them in the App Store and you can get more information by calling 800.331.0500 or visiting an AT&T store.