Opening a bank account in Cambodia is not difficult and will save you money in the long run.

Banking in Cambodia: be prepared to remove your helmet.
Many expats choose to keep their bank accounts from home open and use them as their primary source of cash, but with ATMs charging up to $8 per transaction for foreign cards in Cambodia (and the home banks often charging the same), it makes sense to open a bank account in Cambodia if you’re going to be here for more than a couple of months.
If you’d like to open an account, the best way to do so is in person. To open an account at most banks you will be asked to show a valid long-stay visa, a work permit or letter of employment, and often a lease. It is no longer possible to open a bank account as a tourist, although some entrepreneurial souls have managed.
ATM machines abound, although most charge a hefty $6 or $7 fee for international cards. The exception is Canadia Bank, which charges no fee on ATM transactions for European bank accounts (unfortunately, they are no longer free for Americans). You can find red Canadia ATMs at the airports. Find out more about the ATMs with the lowest fees in Cambodia.
All ATM machines that accept foreign ATM cards dispense US dollars. Most will not dispense riel unless you have a local bank account. Another thing to note is that the ATMs in Cambodia tend to dispense $100 and $50 bills, and most businesses can’t make change for bills this large. So plan your purchases carefully and try to break large bills whenever you can–hotels, grocery stores, and tourist-oriented restaurants are good bets.
Setting up a bank account in Cambodia is relatively easy. Most banks require a passport with a valid long-stay visa and a copy of your lease or an employment letter.
ABA Bank (ababank.com), a subsidiary of the National Bank of Canada, is now the bank of choice for most expats and locals in Cambodia, due to their fast adoption of QR code technology, which allows you to pay for everything from petrol to beer with your ABA app.
J Trust Royal Bank (anzroyal.com) was once the most popular choice for expats due to its former relationship with Australia-based ANZ bank; it’s now majority owned by J Trust. They have branches in Phnom Penh, Siem Reap, Poipet, Battambang, Kampong Cham, and Sihanoukville and 127 ATM locations across Cambodia.
ACLEDA Bank (acledabank.com.kh) is one of Cambodia’s largest banks, with more than 230 branches in the country–there’s one nearly anywhere you’d want to go. They offer online bill payment to the utilities companies and some of the mobile phone carriers, as well as internet banking. Opening a current account at ACLEDA requires a minimum opening deposit of $1,000 in US dollars or nine other currencies and an ongoing balance of $500 or more.
Canadia Bank (canadiabank.com.kh) is one of the largest local banks in Cambodia and another expat favorite. They offer fee-free withdrawals from their ATMs. They have nearly 40 branches with 50 ATMs across the country. Current accounts are available in Cambodian riel, US dollars, and Thai baht and require a $200 minimum deposit. Bring your passport with valid visa.