One euro a ride if you are visiting. Free — 100% subsidised — if you have permanent residence in the Municipality of Piran, if you hold an Okolje Piran parking permit for Piran town, the Fornače car park or the Arze garage, if you are a disabled passenger (and one companion travels free with you), or if you are a child under 12.
The free travel is not automatic. You have to activate an Arriva contactless EMK Piran card or the Arriva Piran app in person with an ID document, and the entitlement then lasts one year from activation and has to be renewed. Residents and permit holders can do it at Okolje's office on Dantejeva ulica in Piran on Monday, Wednesday and Friday between 08:00 and 14:00; residents can also use Arriva's office at the main bus station in Lucija, Monday to Friday 08:00–16:00 and Saturday 08:00–13:00. Both can be done remotely as well.
Paying as a visitor: contactless bank card or the Arriva Piran app on board, or buy before you travel. The EMK Piran card itself costs €3.50. Whatever you use, validate it on the reader fitted inside the minibus.
The Arriva city buses to Portorož, Lucija and Strunjan leave from the bus station on Dantejeva ulica, beside the Fornače car park — that is the way to the health centre, the banks and the big shops. Those are a separate operator with a separate fare; see “Buses out of Piran” on this town's page.