ZOHO Phone Checker extension
Real - the phone number is real.
Zoho Phone Checker FAQ
I've created Contact(Lead). Why is phone status not changed for a long time?
Status can be updated in period from 10 minutes up to 2 hours! Also, you may be already out of API calls limit of your Zoho CRM.
Why is the contact status not updated after changing the phone number?
Change the phone number of the Contact/Lead, refresh the page, you'll see phone status Request is in progress and in some time the phone number will be checked and you'll see one of the possible statuses: Real, Fake, Unknown, Out of limit.