How to add trusted devices to Google two-step verification?

Question

Google provides instructions for how to add a device to its two-step verification.

Add trusted computers and devices

Sign in on a computer or device you trust.

When you enter a verification code, select Don't ask again on this computer.

Unfortunately, these are inadequate. For example, on many devices I wish to add, I am already signed in. When I sign out and sign back in, there is no request for a verification code (so I can't select "Don't ask again on this computer"

Motivation

The reason for wanting to add more devices as trusted devices is because I recently updated my phone and Google's two-step verification will only allow me to carry out the second step of the verification on the old device. Thankfully, I hadn't yet wiped/sold it! Getting locked out of a Google account over something so poorly thought through would be disastrous.

Question

How do I add more devices as trusted devices for the purpose of two-step verification? (so that if one is not available, e.g. it's been sold, then I can do so on another device)

Answer 1

Google uses Google Authenticator for 2FA access. When you set up your 2FA there are 10 one-time use codes that you can use to regain access in the case of a lost device. Here is a link to find your codes (they recommend you print or save them somewhere safe)

Also as a backup, you can screenshot the QR code used to transfer your authenticator from one device to another to maintain access to your account. I used this method just this past year when my phone screen broke and stopped responding to touch. You would start the export and take a picture but then not complete the transfer. There are instructions for getting the QR code (for transfer) at this link and they also have instructions on setting up Google Authenticator on multiple devices for your 2FA codes.

Answer 2

Google uses multiple signals to decide whether a particular device can be trusted for certain actions like changing password, adding 2FA token, changing recovery phone number / recovery email etc.

These can include:

• Most recent successful login,
• Activity (how long has this device been signed into, and has been in use),
• Geographic location,
• Type of device, etc.

You can try this:

1. Sign out of the new device if you're already signed in - If you're using Chrome, click on the profile icon in the "New tab" page and click "Sign out of all accounts". The link should look like https://accounts.google.com/Logout?ec=<some code>

2. Navigate to https://myaccount.google.com/device-activity (requires signin). There you will find all the devices that you are signed into.

3. Click the three vertical dots next to the new device to open the menu and choose "Sign out".

4. Go back to the new device and try to login again.

You should be asked your auth token again.