This depends on how you word your claim combined with the report or quote made by the roofing company. If there has been a storm and high winds have blown off some tiles, or a tree has fallen on the roof, something like this, then it is normally covered. If it is leaking because it is old and needs replacing then it would not normally be covered. Many roofs are over 100 yrs old, have no roofing felt and are leaking in many places including around the chimney flashing (if it has any). First thing is to get the roof inspected. It is quite urgent because the roof timbers will rot if constantly wet.
Regards,
Paul Albright