The official currency of Croatia is now the Euro.  It replaced the Kuna on 1st January 2023.

We recommend purchasing your travel money before you leave the UK. You can exchange Sterling at a local post office or bank. Alternatively, you can order online from Thomas Cook Travel Money, or if you don't like carrying cash, why not use a travel money card? This offers an efficient way to keep all of your spends in one place. And with extremely competitive rates, your money will stretch even further. 

If you plan on paying by card it may also be worth having some notes on you as some smaller restaurants and cafés may not  accept credit cards.