Yes, you can—and must—use euros in Split, Croatia. As of January 1, 2023, Croatia officially adopted the euro (€) as its sole legal tender, replacing the Croatian kuna (HRK). By 2026, the transition is completely finished, and you will find that all shops, restaurants, ferry operators, and hotels in Split exclusively accept euros. While you might still see some old prices listed in kuna for historical comparison in certain local markets, the kuna is no longer accepted for payments. Standard credit and debit cards (Visa/Mastercard) are widely used throughout Split, and you can withdraw euros from any local ATM. If you happen to have old kuna banknotes left over from a previous trip, you can no longer exchange them at commercial banks; you would need to visit the Croatian National Bank in Zagreb for a permanent exchange service. For your visit to the Diocletian's Palace or a day trip to the islands, you should ensure you have a mix of euro coins for small purchases and a contactless card for larger transactions.