Different pricing systems are implemented in VR's commuter services as for the Helsinki Metropolitan (HSL) Area and locations beyond the HSL Area.
From 1 January 2014 you can travel from Helsinki to Kerava and Kirkkonummi with an HSL ticket. Kerava and Kirkkonummi form HSL's third extended region (Extended region 3).
A HSL (Helsinki Metropolitan Area) ticket is needed for travelling by commuter train within Regional transport (Helsinki, Espoo, Vantaa, Kauniainen). Regional transport is delimited by a yellow line in the below map.
Should your commuter train journey connect with a long-distance journey, you may purchase a long-distance ticket including a commuter connection.