You just downloaded the newest, shiniest contacts management app to your smartphone, linked it to your G Suite account to sync with your Gmail Contacts, and now you’re waiting for your mobile address book to fill with everyone you’ve ever known.

And now all your contacts are gone from Google and your phone.

This happens more than you’d think, largely because too many apps make it too easy to set your empty smartphone address book to overwrite your up-to-date Google Contacts list, rather than the other way around.

Fortunately, Google Contacts has built-in versioning functionality so you can “roll back” your Gmail Contacts to an earlier state, restoring any lost contacts in mere seconds. Here’s how it works:

  1. Log into your Gmail account via the web

  2. Click on the Gmail in the top left

  3. When the dropdown appears, select Contacts

  4. In the top level navigation, select More

  5. When the dropdown appears, select Restore Contacts

You’ll have the option to roll back your entire Gmail Contacts list to any saved state—which is to say, any time you altered the data in your Google Contacts—within the last 30 days. In the case of a full overwrite that deleted all your Gmail Contacts, just roll back to the save point right before you installed the destructive smartphone app.