In this article, we will tell you how to change the trusted phone number on iPhone, to which the iCloud security code will be sent, if you forgot your password or want to log in on another device.
Steps

Step 1. Launch the Settings app
Click on the gear-shaped icon on a gray background; this icon is on the home screen.
If this icon is not on the main screen, look for it in the Utilities folder

Step 2. Scroll down and tap iCloud
You will find this option at the top of the fourth section (under the "Privacy" option).
If you haven't signed in to iCloud on iPhone yet, enter your Apple ID and password

Step 3. Tap your Apple ID
This is the first section at the top of the menu.

Step 4. Click Password & Security
This is the second option on the menu.

Step 5. Click Add Trusted Phone Number
You will find this option in the third section of the menu.
If this option is not available, activate the option "Two-factor authentication" in the second section of the menu (to do this, follow the instructions on the screen)

Step 6. Enter the phone number to be trusted

Step 7. Select the method of receiving the code to verify the new phone number
To do this, click "Text message" or "Phone call".

Step 8. Click Submit
You will find this option in the upper right corner of the dialog box.
- A dialog box will open on your smartphone in which you need to enter a six-digit verification code.
- The six-digit code will be sent to the entered phone number in the form of an SMS message or communicated during a phone call.

Step 9. Enter the received verification code
The new phone number appears in the list of trusted phone numbers.

Step 10. Click on the old phone number that you want to replace

Step 11. Tap Delete Phone Number

Step 12. Click Remove
You have now set up a new trusted phone number to verify your iCloud identity. From now on, security notifications and verification codes will be sent to this phone number.