Singapore Airlines (SIA) generally doesn't maintain large physical offices in every city like Helsinki for direct walk-in service instead, they offer extensive online/phone support, use local GSA (General Sales Agent) partners for ground handling (like for Finnair at HEL), and handle bookings/support via their global helpdesk or website, so for Helsinki, check their website for local contact numbers or book online. Jauntlet.comhttps://jauntlet.com/