Leave nothing behind when your number or address changes
Phone numbers and addresses live in dozens of systems that never talk to each other. When you cancel a SIM or move house, the copies left behind become someone else’s problem — or someone else’s opportunity. These checklists put the steps in the order that avoids lockouts.
Why this site collects nothing
A site that “scans” whether a number or address is registered elsewhere would need your data and unofficial access to other companies’ systems — the same machinery scammers use. The safe version is this: correct ordering, official links, and your own eyes on your own accounts. Ticks stay in your browser.