The official currency of Hungary is Hungarian forint (HUF). However, some stores now accept the euro as well, but the change back is always received in HUF, usually exchanged in a rate significantly worse than at exchange offices.
There are several banks in Hungary. The biggest ones, according to the number of branches, are OTP Bank, K&H Bank, Erste Bank, Budapest Bank and CIB Bank.
To open a bank account, you'll need an ID and a residence permit in most cases. You may also need a document showing your address as well. Usually you have to do it personally, but in several cases the bank offers the opportunity to open the account via video call.
Banks are usually open between 8.00 - 16.00 on weekdays. Only banks in shopping centers are open for longer. International chain stores, bigger stores as well as downtown bars and restaurants usually accept bank cards, but it may be advised to be carrying cash as well, as the usage of bank cards is still not widespread. ATM machines are accessible throughout the country. The most often used credit/cash cards — AMEX, Diners Club, EnRoute, Euro/Mastercard, JCB, VISA — can be used to withdraw cash from banks and ATM machines and to pay bills in certain restaurants and shops. Emblems at the entrance indicate which cards are accepted at the store.
Express international money transfer services at Western Union are also available in Hungary.