With a single ticket you can hop on trams, buses, the metro and even the ferry to Suomenlinna. Day tickets available for 1 to 7 days allow unlimited travel on public transport. Buy your ticket in advance using the HSL app, from ticket machines or from sales points, including kiosks and several shops https://www.hsl.fi/en/tickets-and-fares/sales-points. NB! Due to the corona virus situation, ticket sales is suspended at HSL service points in Helsinki Central Railway Station and Itäkeskus from 25 November 2020.
HSL area is divided into four zones, designated by the letters A to D, spreading out from the center of Helsinki. Buy a ticket for all the zones you travel through. In zones A, B and C, you always have to buy a ticket for at least two zones (an AB or BC ticket). NB! There are no one-zone tickets for zones A, B and C. An ABC ticket allows you unlimited travel in Helsinki, Espoo, Kauniainen and Vantaa.
When you search for routes and timetables with the Journey Planner, it tells you which ticket you need for your journey. https://www.hsl.fi/en
Helsinki Card holders can travel free of charge on public transport. Helsinki Card City includes free public transportation within the the travel zones AB, while the Helsinki Card Region can be used for traveling with the travel zones ABC. Helsinki Card Region can be used for traveling from/to the Helsinki Airport. https://www.helsinkicard.com/
HSL’s Service Point: Central Railway Station Metro Station, Mon–Fri 7.30 am–7 pm, Sat-Sun 9.30 am–5 pm.
Helsinki Region Transport www.hsl.fi/EN