AT&T vs T-Mobile for an iPhone 18 Pro
Both carriers, same phone, same 36 months — with the plan, the phone, the fees and the trade-in all counted.
T-Mobile is $720 cheaper — $3,034 against $3,754 over 36 months, buying the phone outright and bringing it to each carrier's cheapest plan.
Cheapest route at each
| AT&T | Plan | 36 months |
|---|---|---|
| Extra 2.0Buy from Apple, bring your own | $70/mo | $3,754 |
| Premium 2.0Buy from Apple, bring your own | $90/mo | $4,474 |
| Elite 2.0Buy from Apple, bring your own | $110/mo | $5,194 |
| T-Mobile | Plan | 36 months |
|---|---|---|
| Essentials Saver 2.0Buy from Apple, bring your own | $50/mo | $3,034 |
| Essentials 2.0Buy from Apple, bring your own | $60/mo | $3,394 |
| Experience More 2.0Buy from Apple, bring your own | $85/mo | $4,294 |
If you are switching with a phone to trade
Every phone promotion at both carriers needs a port-in, a trade-in or both, so none of them apply to the figures above. Priced again as a switcher trading in an iPhone 16 Pro — which Apple values at $510 — T-Mobile comes out $520 cheaper: $2,524 on Essentials Saver 2.0 against $3,044 on Extra 2.0.
Both of those winning routes still buy the phone from Apple. That is the usual result: once the phone you hand over is counted at what Apple would have paid for it, the bill credits rarely cover what the deal costs you.
How this is counted
Everything over 36 months: the plan, the phone after any bill credits, one-time fees, and — the step most comparisons skip — the phone you hand the carrier. A phone traded into a deal for bill credits is money out of your pocket at exactly what Apple would have paid you for it. Buying from Apple instead sells that phone to Apple, so its value comes off the price rather than being given away.
Taxes are excluded. T-Mobile, AT&T and Verizon prices assume AutoPay; Xfinity's include the internet-customer discount. Anything a carrier does not publish is flagged rather than guessed.
Sources
https://www.att.com/plans/unlimited-data-plans/
https://www.t-mobile.com/cell-phone-plans