From the FAQ section: "Can Ühiskaart be returned? You pay a €2 deposit when purchasing a Smartcard. Ühiskaart can be returned within six months from the purchase of the card.
Smartcard fares: •1-hour ticket - €1.10 For this type, one Smartcard can be used … First, validate your ride, then choose the number of extra rides to be purchased using the arrows, then press OK and swipe your QR-ticket again. You can personalise your Smartcard via the link above, through online banking, Mobile-ID, mobile phone or at Post Offices or the Tallinn City Government service desk (Vabaduse väljak 7). If you are eligible for discounts, you must personalise your Public Transport Card in order to make use of them. Personalizing cards online (www.pilet.ee) or in the public service office (Vabaduse väljak 7) or other sales points of Tallinn City Government is free of charge. An impersonalized Ühiskaart can be returned to the Tallinn City Office Service Hall (Vabaduse väljak 7), Tallinn's Old Port A- and D-terminal, R-kiosks, Tallinn airport R-kiosks, the Baltic stations R-kiosk and T-Pilet sales point located in Tallinn Bus Station. Elsewhere the service costs €1. QR–ticket (1 hour 1,50 €). Single fare from the bus/tram/trolleybus driver – 2.00 € However, it is advisable to buy a reloadable Tallinn "Green Card" (Smartcard) for 2 €, without the need to personalise it. R-kiosks at Tallinn Airport, Railway Station (Balti Jaam) and Tallinn Port. Tallinn airport R-kiosk; Passenger port A and D terminal R-koisk; Train station R-kiosk You will need to validate your smartcard when entering a vehicle. You can either load money or e-tickets to it (over the Internet or at the R-kiosks). Although Tallinn is a compact city in which you can easily walk to most destinations, the city offers organisers of international events (conferences, cultural and sports events) the chance to apply for the right to use public transport free of charge for the participants of their events. Purchase online at tallinn.pilet.ee or with the mobile app Pilet.ee. Share them with your friends and family. Non-personalised Smartcard and balance up to 20€ can returned. You must, however, have a validated ticket or you risk a €40 fine. That I’d either be paying for public transport for the rest of my time in this city, or that I’d be forced to catch buses illegally, constantly on edge as I watched for ticket inspectors (cue the smallest violin in the world). For international students who have registered their place of stay as Tallinn (City District Government Office) and acquired a smartcard for transport, public transportation is free of charge. Purchase up to 10 rides onto your QR-ticket. Some riders are entitled to use the system for free: children under school age (under 7), an adult travelling with a child under 3 years of age, registered Tallinn residents (using a personalised Smartcard and carrying ID). Customer service desk of Tallinn City Govenment (Vabaduse väljak 7) Information desk of Central Bus Station. Use the front door validator with the QR-scanner. Tallinn public transport ticket information and fares are published on their website and schedules of public transport by vehicle/stops can be found here. Tourists can purchase a non-personalised Smartcard. After my first failed attempt to use free public transport in Tallinn, I was worried that it would never happen for me.