In Rotterdam, the euro is the legal tender. Practically anywhere in the town, you can pay at every register with cash, PIN and chip-cards. Do you need cash money? ATMs and banks are always close by, particularly in the city center. If you need to exchange other currency into euros, you can use e.g. the services of GWK Travelex at Stationsplein (next to Central Station) and at Rotterdam The Hague Airport.