Is iCloud required for iOS update?

Do you have to enter your iCloud account for updating iOS? I cannot use my current account since it's connected to an old number which is long gone hence I cannot verify it or even use it. Will a different Apple ID suffice?

I know iCloud is used to backup data but I don't use it that much but I don't want to get locked out from my phone permanently.

Solution 1:

Short answer to your question is "No." Updates do not require you to verify your phone number.

But as you said you no longer have access to your phone number linked to your iCloud account, you should update your current number in iCloud as soon as possible (here is how).

It is also recommended to backup the phone before updating, so you may want to fix your phone number issue first and use iCloud backup to make things easy.