Setting up a new iPhone is only half of an upgrade. The old one can still contain years of personal information, remain attached to your Apple Account and, depending on how the migration was handled, provide a useful safety net until you are certain everything transferred correctly.
The most important thing is not to erase it immediately. Finish setting up the new iPhone first, then check Photos, Messages, Contacts, Notes and any files you keep locally. Open banking and authenticator apps, make sure your phone number is active on the new device and confirm anything particularly important has made the move.
Apple’s Quick Start can transfer data directly between devices or restore it through iCloud. Apple recommends keeping both iPhones nearby and connected to power while a direct migration is taking place.
Decide whether to keep, sell or trade it in
Keeping an older iPhone can be useful as a spare, particularly for travel or emergencies. If it is staying in a drawer, charge the battery periodically rather than leaving the device completely discharged for months.
Selling privately can sometimes return more money than a trade-in, although it requires more effort. Apple Trade In and carrier trade-in offers provide a simpler route, particularly when buying a new iPhone, but it is worth comparing the value before handing over the old device.
An older iPhone can also be passed to a family member. In that case, erase it properly and let the new owner set it up with their own Apple Account rather than simply deleting your photos and apps manually.
Erase it only when you’re ready
Before selling, trading in or giving the phone away, unpair an Apple Watch if necessary and follow the iPhone’s erase process in Settings. Signing out and erasing the device removes personal information and prepares it for its next owner. Make sure Find My and Activation Lock have been dealt with as part of that process.
If you use eSIM, confirm cellular service is fully working on the new iPhone first. With supported carriers, the old SIM can be deactivated as the plan moves to the new device, so there is little benefit in rushing the erase until calls, messages and mobile data have been tested.
Anyone upgrading to iPhone 18 Pro or iPhone 18 Pro Max has until the first deliveries begin on September 18 to decide what to do with the outgoing phone. Preparing it now can make launch-day migration considerably less stressful.