on999A sn on a beach in Whitstable, United Kingdom, advising readers to dial 999 and to request for the coastguard in the event of an emergency. 999 is an official emergency telephone numberPhone providers display 999-999-9999 when a number cannot be captured. There are a few reasons why this could be: The caller blocked their number from showing up on your caller ID using codes such as *67 or #31#.