In the early days of the iPhone, users upgraded their device especially often. But as the product matured, and carrier deals changed, the upgrade cycle started getting longer. Now, it seems, that trend is starting to reverse.iPhone upgrade cycle just got shorter for a lot of usersCIRPs latest report highlights a change in iPhone upgrade patterns seen during the most recent quarter, ending in December 2024.Michael Levin and Josh Lowitz write:There were more iPhone buyers retiring younger phones compared to earlier quarters. Specifically, 36% of iPhone buyers in the December 2024 quarter reported having their previous phone for two years or less, compared to 31% in the December 2023 quarter.Conversely, slightly fewer buyers had a phone for three years or more (33%) or for two to three years (30%) compared to 2023. The shift from 2023 to 2024 was divided evenly between these two categories.For years, investors and analysts have stressed over the question: How often are users upgrading to a new iPhone?Its an important question. If you have a lot of people buying a new iPhone every two years, that will make a huge sales impact. But if users hold on to their iPhone for 3, 4, 5+ years, theres a similar impact in the wrong direction.9to5Macs TakeCIRPs data seems to show what I suspect is an Apple Intelligence impact. Users of the iPhone 15 (non-Pro) and older had AI features as a fresh incentive for upgrading sooner than they might otherwise.This theory is supported by Tim Cooks recent statement that the iPhone 16 was outperforming the iPhone 15, and sales were especially strong in markets where Apple Intelligence had launched.What do you attribute the changing iPhone sales trends to? Do you think its Apple Intelligence, or not? Let us know in the comments.Best iPhone accessoriesAdd 9to5Mac to your Google News feed. FTC: We use income earning auto affiliate links. More.Youre reading 9to5Mac experts who break news about Apple and its surrounding ecosystem, day after day. Be sure to check out our homepage for all the latest news, and follow 9to5Mac on Twitter, Facebook, and LinkedIn to stay in the loop. Dont know where to start? Check out our exclusive stories, reviews, how-tos, and subscribe to our YouTube channel