Following Apple's announcement of the iPhone 12, it was discovered that the T-Mobile and Sprint versions were $30 more expensive than the AT&T and Verizon models because of "special offers" available from the latter two carriers. Now T-Mo and Sprint get those discounts, too.
T-Mobile and Sprint customers now pay the same price for an iPhone 12 and iPhone 12 mini as AT&T and Verizon subscribers when buying from Apple. That means that the iPhone 12 starts at $799 and the iPhone 12 mini at $699 after the $30 instant discount, which requires an activation.
The SIM-free version of the iPhone 12 still starts at $829, so you'll pay a premium if you want an unlocked iPhone 12 without activation.
It's also worth noting that the iPhone 12 is still priced at $829.99 from T-Mobile, despite Apple lowering its price today. There's no word on whether T-Mo will adjust its price to match Apple's.
T-Mo and Sprint customers who do buy an iPhone 12 from Apple can get an extra $150 trade-in credit with they trade in an iPhone 8 or higher in good condition. That $150 credit will be given to you as a virtual prepaid Mastercard rather than doled out in monthly installments like T-Mobile's iPhone 12 deals are.
When Apple introduced the iPhone 12 earlier this week, it said that the phone would start at $799, so T-Mobile and Sprint customers were likely confused when Apple's pricing for them was $829 while AT&T and Verizon subscribers got that $799 price. It's unclear exactly why T-Mobile and Sprint were excluded from this $30 discount initially and why it's now being applied, but hey, at least now the price of the iPhone 12 is the same across all the major US carriers.