Advice on the road
Fill the tank using CCS cards placed in a car. CCS cards can pay for car wash or windshield washer liquid too. The cars are valid in the Czech republic as well as in Slovakia. You can use the following mobile application to find a petrol station accepting CCS: http://www.ccs.cz/mobilni-aplikace-tank-navigator.
You can either use a “Tank Navigator” mobile app - https://goo.gl/5co1Pg or look for the CCS logo at the petrol station entrance.
If you cannot pay by CCS you can use any other means to pay for fuel. You have to take a tax receipt, mark it with your name and put it to the envelop in the car. For quick billing, upload the receipt to the application via the "Cashback" button, more information here.