It’s that time of year when those upgrading to a new iPhone wonder if they can save a few bucks and stick their old case on a new phone. In recent years, it’s been unlikely.
Last year was a prime example. Apple introduced a new button, the Action Button, to its higher-end phones, the iPhone 15 Pro and 15 Pro Max. This meant that even if your older case had fit (which it really didn’t), you absolutely shouldn’t have used it.
If you had a non-Pro iPhone and were upgrading to an iPhone 15 or iPhone 15 Plus, the question about using an older case was less obvious. But Apple gave its iPhone 15s contour edges and redesigned corners, so while an older case still technically fit, it didn’t fit well.

With this year’s iPhone 16 lineup, the answer is more blatant than ever. That’s because Apple gave all four iPhones 16 — not just its Pros— another new button: the Camera Control button. It also gave the non-Pros the Action Button that was exclusive to last year’s Pros.
This means that no matter what older case you have, you shouldn’t use it on an iPhone 16 — no matter the model — because it’s going fit over or be compatible with the new buttons.
Still, we’re here to do the hard yards. If you’re in a pinch and don’t want to upgrade to a new case, or maybe you really love the feel or patina of your older case, we’ve tested how each older case fits on its iPhone 16 successor.