There's popular app in Bangalore that you can use to rent bicycles. I can't use it because my phone number (which has a relatively newly released starting digit series) doesn't pass their signup validation.
So much this. Iran's phone number formats have changed at least 4 times in the past 20 years, and I am sure many more times if you go back a couple more decades.
Vietnam just removed a few months ago one digit of all the mobile phones making all the previous number recorded for the country invalid.