Turn on the new iPhone and place it near the old iPhone
Make sure both iPhones are connected to Wi-Fi and have enough battery
Follow the Quick Start prompt on the old iPhone
Use the old iPhone camera to scan the animation on the new iPhone
Enter the old iPhone passcode on the new iPhone
Set up Face ID or Touch ID on the new iPhone
Choose Transfer from iPhone or Download from iCloud when prompted
Keep both iPhones close together until the transfer finishes
Sign in with your Apple ID if asked
Wait for apps, photos, messages, and settings to finish syncing
If needed, transfer your SIM or activate eSIM on the new iPhone
Check that contacts, photos, apps, and messages are on the new iPhone
Erase the old iPhone only after confirming everything transferred correctly