I’ve lost my phone and I want to block the phone to prevent anyone from using it. Is that possible?
iPhone XS, iOS 16
iPhone XS, iOS 16
Don'ts
If the device is removed from an account after it is erased, Activation Lock will be turned off. This allows another person to turn on and use the device.
An example of my iPhone 5 is given in the GIF below. There is no "Undo" after you remove it from your account.

iPhones are designed with strong security measures to protect the privacy and data of their owners. One of the key features that ensure this is the requirement of an Apple ID and password or a passcode to access the device's contents. This means that without the owner's authorization, it is nearly impossible for anyone else to open an iPhone and gain access to its data.
With these security measures in place, iPhones offer a high level of protection against unauthorized access. Even if someone physically possesses the device, they will find it extremely challenging to access its contents without the owner's Apple ID and password or the passcode. This helps safeguard sensitive information, personal data, and ensures the privacy of the iPhone's owner.
It is worth noting that while these security measures provide strong protection against unauthorized access, it is essential for iPhone owners to choose strong and unique passcodes or passwords. This minimizes the risk of brute-force attacks or password-guessing attempts.
These are the steps you can perform in such a situation:--> If your iPhone, iPad, or iPod touch is lost or stolen,
and/or:--> Use the Find My app to locate a missing device or item,
and/or:--> If Find My is offline or not working
and/or:--> If Find My iPhone or Find My iPad isn't enabled on your missing device
Regards and best of luck.
Giulio
I’ve lost my phone and I want to block the phone to prevent anyone from using it. Is that possible?