Yahoo Helpline Number, Yahoo is a famous web based service providing company. It is an American company that started from 1995 and till then its user has grown tremendously. Yahoo mail services are widely used services all around the world. Millions of users use web based mail services provided by yahoo. Yahoo mail services are used for both personal as well as professional use. It is available free of cost for all who have a yahoo account., London, 0800 410.