ATMs are available and credit cards are widely used in cities. Cloning of credit and debit cards is common. You should be vigilant when using ATMs and not let your card out of your sight during transactions. Outside cities you should make sure you have sufficient cash in local currency.
The official currency of Ukraine is the Hryvnia (UAH). US dollars and Euros are the easiest currency to exchange in Ukraine. Sterling may also be exchanged at a more limited number of sites. Scottish and Northern Irish notes aren’t accepted. You should only use official exchange booths and make sure you’re given a receipt.
You’ll need to present your passport if you wish to exchange currency worth 150,000 UAH or over. Keep the receipt as you may need to produce it if you exchange money back on departure.