Handling money in Finland is refreshingly simple. The country is one of the most cashless in the world, so a card is really all you need in Ruka.
Here's the quick guide.
Currency
Finland uses the euro (€). You rarely need cash — even small purchases, cafés and remote spots take cards.
Cards & cashless
Finland is almost entirely cashless. Visa and Mastercard (and contactless/Apple Pay/Google Pay) are accepted virtually everywhere. Keep a small amount of cash only for the rare exception, though it's seldom needed.
Tipping
Tipping is not expected in Finland — service is included and staff are paid fair wages. Rounding up or leaving a little for exceptional service is appreciated but never required.
Costs
Finland is a Nordic country and not cheap, but Ruka can be done well on a range of budgets — see our budget aurora guide.