I learned this lesson the hard way with an old flip phone in 2012. The phone died, and with it went every number I had saved since high school. I rebuilt my contact list from memory, badly. Now, before I switch phones, backing up contacts is the first thing I do, and it takes about five minutes.

Modern phones make this painless, but only if you know where the switch lives.

On iPhone: iCloud or Google

On an iPhone, go to Settings, tap your name, then iCloud, and make sure Contacts is toggled on. That syncs your contacts to iCloud automatically.

If you are moving to an Android phone, install the Google Contacts app and let it pull from iCloud. When you sign in on the new phone, your contacts follow.

On Android: Google Is the Answer

Android phones back up contacts to your Google account automatically. To check, open Settings, Accounts, your Google account, and verify contact sync is enabled.

Before switching, I open contacts.google.com on a computer and confirm the list looks complete. Seeing them on a big screen is the fastest way to catch a missing group or a half-synced number.

Export a File for Extra Safety

For the paranoid approach, which I now am: export your contacts to a file.

• iPhone: iCloud.com, Contacts, select all, export vCard
• Android: contacts.google.com, Export, download a vCard file

Keep the file in your email or a cloud folder. If anything goes wrong during the switch, you can import it back in minutes. I have a folder called Phone Exports with one file from every phone I have owned since 2012.