It's not often that you see carriers reduce the price of their unlimited plans, but that's exactly what Metro by T-Mobile is now doing.

Starting February 6, customers who switch to Metro by T-Mobile will be able to get a single line unlimited LTE plan for just $40 per month. This is a $10 discount off the existing price, saving $120 for the entire year. In addition, they can purchase an iPhone 7 for just $49.99. In addition, if you open two new lines, you can purchase an iPhone 7 for $49.99 and get the second one free.

Metro by T-Mobile is our favorite budget phone carrier. In our best cell phone carrier review, Metro by T-Mobile beat out other low-cost carriers like Boost and Straight Talk. Its unlimited data plans are particularly attractive, and its latest contract is noteworthy.

As for the iPhone 7, sure it's a few years older, but it's still a solid iPhone for those who don't need a cutting-edge phone; 4.7-inch Retina HD display, A10 Fusion chip, single 12MP wide camera, 1080p HD video 7MP FaceTime camera with and TouchID. It is also water resistant (up to 30 minutes at 1 meter) and Apple Pay compatible. By comparison, the iPhone 7 typically sells for about $150 or more on Amazon.

This Metro by T-Mobile promotion will launch on Thursday, February 6.