Don't Buy A Used iPhone If It's Older Than This In 2025

Apple announced iOS 26 at the annual Worldwide Developers Conference (WWDC) in June 2025. iOS 26 will come pre-installed with the iPhone 17 series, expected to be unveiled in September 2025 — that's why September is typically the best time to get a good deal on Apple's flagship product. 

Featuring a number of interesting innovations and an entirely new design, this new operating system requires an A13 Bionic chip and is not compatible with all iPhone models. The oldest iPhones compatible with iOS 26 are the iPhone 11 series (iPhone 11, iPhone 11 Pro, and iPhone 11 Pro Max), which debuted in September 2019. So, if you purchase an iPhone released before September 2019, you will not be able to install iOS 26.

If you're in the market for a new iPhone, you should not spend money on a device that isn't compatible with the latest Apple features or new apps, nor should you expose your private data to potential security risks by using a phone that no longer receives software updates and patches. 

Concerns about the security of old iOS versions are not merely theoretical. When an operating system is outdated, it is vulnerable to so-called zero-click vulnerabilities, which exploit inherent and already identified weaknesses in the system without the user needing to interact with a malicious program or website.

But it's not just security you need to worry about with an old iPhone. iPhones use lithium-ion batteries, which degrade with time. After three years of use, battery health can drop to 75% of the original capacity. The older an iPhone is, the more it will struggle to run the latest apps smoothly, leading to slower performance and more frequent crashes.

All products that have been discontinued for seven years or more are considered obsolete by Apple itself. As a general rule, you should avoid iPhones that are close to or past this mark. Aim for the newest model you can afford. Used models can be a decent budget option, but you should read up on the differences between refurbished and used iPhones before making any decisions.