わたしの部屋

Phase 0: Audit before anything moves (15 minutes, the week before)#

Check the photo backup’s “last successful” date. Not the toggle — the date. A backup that has been silently paused for three months because storage filled is the number one cause of “the new phone is missing last summer.”

List what lives only on the device. For most people: authenticator apps (many don’t sync), messaging history if not backed up, health data if not synced, and the notes that were never in any cloud. Anything on this list needs a deliberate move, not an assumption.

Check the 2FA backbone. Go through critical accounts — email, bank, password manager — and confirm each has a recovery path that doesn’t require the old phone specifically: a backup code, a second device, or an email recovery. Print fresh backup codes for anything you can’t confirm.

Phase 1: The transfer, in order#

1. New phone on, signed into the same accounts, updated. Let the platform’s transfer tool do the heavy lifting (device-to-device migration moves app data, messages, settings). Do this with both devices on the charger and don’t skip the “transfer data” prompt in favor of “set up fresh” unless you enjoy re-creating logins.
2. Restore the authenticator from its backup/transfer function specifically — it does not ride along with the general transfer on every platform and app version. This is the step people assume happened.
3. Open and log into the money apps manually: bank, payment apps, the carrier app. They’ll want fresh verification — good, that’s the moment to confirm 2FA lands on the new device.
4. Wearables and smart-home devices: re-pair. Tedious but mechanical.

Phase 2: The week of parallel running#

Keep the old phone on WiFi for a week before wiping it. The parallel week catches the stragglers:

• The app that can only be logged into from the old device (games with device-bound accounts, banking apps with one-device policies)
• The SMS-based verification you forgot was still going to the old SIM
• The photo or note someone assumed “synced”

WARNING

The SIM/number move is its own trap. Port the number to the new phone, but for a week afterwards treat the old number as still dangerous: some services take days to accept that a number moved devices. Never factory-reset the old phone on porting day.

Phase 3: The old phone leaves safely#

Only after the parallel week:

1. Sign out of every account on the old device (the account sign-out, not just app deletions — platform sign-out removes the activation/anti-theft binding).
2. Factory reset.
3. If sold or traded: confirm the activation lock is gone by checking the device boots to a fresh setup without asking for the previous owner’s password. An activation-locked phone you sold is a brick for the buyer and a privacy liability for you.
4. If kept as a spare: wipe anyway, then set it up as the household’s backup/backup-check device. A charged spare phone in a drawer has ended more small emergencies in this house than any gadget bought on purpose.

The one-time settings worth redoing on the new device#

Upgrades reset habits along with hardware. While you’re in there: purchase authentication set to every-purchase (not the 15-minute grace window), the photo backup verified on the new device the first night, and the privacy defaults re-checked — a new device, especially if switching platforms, is the cheapest moment you’ll ever have to make these settings right.

The whole thing, done in this order: an evening, a parallel week, and a safe exit. Done in the wrong order: the authenticator story, which I have watched a family member live through once, and which is why this post exists in this specific order.