The best T-Mobile deals for September 2025: new iPhone 17 series, Pixel 10, cheap plans, and more

Apple iPhone 17 series: up to $1,100 off with a trade-in, or $1,000 off with switch at T-Mobile
T-Mobile's opening deals on the iPhone 17 series offers huge discount of up to $1,100 off when you trade in a device alongside a new unlimited line. According to the criteria, the biggest discount is eligible with a trade of an iPhone 13 Pro or newer, but older devices can still get up to $820 off here. If you're looking for a decent non-trade-in option, T-Mobile is also offering an impressive $1,000 rebate when you port your number over from a rival carrier. The switching deal can cover the entire cost of the iPhone Air, whereas the maximum trade-in rebate will cover an iPhone 17 Pro.

Apple iPhone Air: up to $1,100 off with a trade-in, or $1,000 off with switch at T-Mobile
Another superb brand-new iPhone deal from T-Mobile, you can also get those same excellent discounts on the stunning iPhone Air. Either trade-in or switch over from a rival carrier and you'll potentially be able to cover the entire cost of this $1,000 device thanks to a 24-month rebate.

Google Pixel 10 series: up to $1,000 off with a trade, or up to $800 off with a new line at T-Mobile
The latest Google Pixel 10 series is here and T-Mobile, as expected, has some superb deals on these new devices. Available right now is a trade-in rebate of up to $1,000 off on the Pro devices and up to $800 off the standard Pixel 10. If that doesn't appeal, then you can instead get a flat $800 rebate alongside a new line on one of the carrier's pricier post-paid unlimited plans.

Samsung Galaxy Z series: up to $1,100 off with a new unlimited data plan at T-Mobile
New and old customers alike can get massive discounts on both the new Galaxy Z Fold 7 and Flip 7 today at T-Mobile. Right now, you don't even need to trade-in to get a massive discount of up to $1,100 alongside a new line on an Experience More or Experience Beyond plan. If you're not interested in the pricier plans, then you can instead trade-in for a similar discount of up to $1,100 on the Plus plan.

Samsung Galaxy S25 Edge: free with a new unlimited plan at T-Mobile
Another incredible T-Mobile deal on a brand-new Samsung device, right now you can get the latest Galaxy S25 Edge for free with a new unlimited data line. As with the Fold 7 deal above, you'll need a line on the Experience More or Experience Beyond plan to be eligible. That said, you can still trade-in for a significant discount on one of the cheaper plans, too.

Samsung Galaxy S25 series: get up to $1,000 off with a trade-in, or up to $800 off with a new line at T-Mobile
The other devices in the Galaxy S25 range have superb discounts right now too. The biggest of which is a maximum trade-in rebate of up to $1,000 but you can still get $800 off with a new line on one of the pricier plans. Even if you're not looking for a higher-end unlimited plan, you can still get $600 off with a new line on most 5G plans right now - perfect for picking up a cheap Galaxy S25.

Google Pixel 9a: free with a new line at T-Mobile
Finally, T-Mobile is offering $600 off the Pixel 9a on most postpaid lines right now, which is enough to cover the entire cost of this mid-range device. Unlike with some of this week's best T-Mobile deals, this particular promotion isn't tied to one of the higher-end plans specifically, so it's a good choice if you're on a budget.

T-Mobile unlimited plans: get third line free
T-Mobile's best plan deal is the carrier's most well-known. It is, of course, the 'third line free' promotion that's been a staple at the carrier for a few years now. Although single-line users won't find much joy here, families or those with multiple lines will be able to get their unlimited plans down to a minimum price of just $25/mo if they bundle four lines together on the Essentials plan.

Bring your own phone: get Essentials plan for $50/mo
A good option for single-line users, T-Mobile is currently offering a line on its entry-level Essentials unlimited plan for $50/mo when you switch over from another carrier. This equates to a $10/mo saving, so it's definitely worth considering, not least because the carrier will also gift you a virtual prepaid card of up to $800 in value to help pay off your phone at a rival network.

Military, first responder, and senior discounts: get Essentials plan for $50/mo
T-Mobile's unlimited postpaid plans are significantly cheaper if you're eligible for one of the carrier's discount criteria. Eligibility for a discount includes those over 55 years of age, first responders, or active serving military and veterans. You can't stack these discounts, but the savings roughly equate to $10 to $20 per month, depending on how many lines you have, so it's definitey worth applying for if you meet the criteria.

Amplified home internet: $200 back after 10 weeks
It's not just phone plans that are covered in this week's best T-Mobile deals, you can also find some good options if you're looking to switch up your home internet. Right now, for example, the carrier is offering a virtual prepaid Mastercard to home internet users after 10 weeks. Overall, a nice little discount for the first year of your contract.

All-in home internet: $300 prepaid card
And, if you want to upgrade to the high-end All-in home internet package, then T-Mobile's prepaid gift card will also throw in that $300 prepaid card. While pricey, this particular plan includes a handy range extender and subscriptions to Hulu and Paramount+ Essential bundled in.

Samsung Galaxy Tab S10 FE: $275 off with new tablet line
One of the best tablet deals you'll find at T-Mobile this week is on the Samsung Galaxy Tab S10 FE. This mid-range slate packs in a decent chipset and display, so it's an easy recommendation with its massive $275 discount at the carrier this week. A new line is required, however, as with the other tablet deals on our list.

Apple Watch 10: $250 off with a new watch line
The flagship Apple Watch Series 10 has a healthy $250 discount available right now when you bundle it with a new line. While the bonus saving here isn't quite enough to cover the entire cost of a device, you're still getting what's essentially a half-price, premium smartwatch here.

Apple Watch SE 2: $30 with a new paired line
A great budget Apple Watch option, T-Mobile will throw in an Apple Watch SE 2 for just $30 when you pair it up with a new line. While this particular device lacks some of the latest bells and whistles from the higher-end models, it's still a great choice in its own right with a decent chipset, display, and a host of fitness and lifestyle features.

Samsung Galaxy Watch 8: free with a new watch line
Got an Android phone? Right now, you can get a brand-new Galaxy Watch 8 to go alongside your new phone when you pick it up alongside a new watch cellular plan. Considering this device is currently valued at $399, this is easily one of the best accessory 'freebies' available at T-Mobile.