Moving everything to a new phone
Transfers mostly work. What gets left behind is the part you'd miss most.
What's usually going on
Photos and contacts usually make it. Authenticator apps, banking app sign-ins, message history, and anything that was never backed up often don't. You find out weeks later, after the old phone is gone.
Worth trying first
Keep the old phone.
Don't trade it in, erase it, or let the store wipe it until you've used the new one for a few days.
Back up the old phone, and check the date.
Open Settings and search for "backup". Make sure the most recent backup is from today, not last spring.
Use the phone-to-phone transfer.
During setup, put the two phones side by side when prompted. It moves more than restoring from the cloud does.
Move authenticator apps on purpose.
Two-factor codes often don't transfer by themselves. Open each authenticator app on the old phone and use its transfer or export option before anything is erased.
Check the things you'd miss.
Photo count, message history, banking apps, and that calls and texts arrive on the new phone.
When to hand it over
If you're moving between iPhone and Android, if the old phone is broken, or if you'd rather hand over two phones and get one back that works.
Your own technologist, on call.
Tell us a little about your setup. We'll take it from there.