The currency in Sri Lanka is the Sri Lankan Rupee. Currency Notes are in the denominations of Rupees 10, 20, 50, 100, 200, 1000 and 2000. Coins commonly in circulation are in the denominations of 5cents, 10cents, 25 cents, 50 cents, One Rupee, Two Rupees, Five Rupees and Ten Rupees.
It is best if you exchange the cash into Sri Lankan rupee at the airport before you begin your Sri Lanka trip. Try not to exchange your currencies at the hotel as you may not get a competitive rate. Many hotels and shops accept reputed Credit cards. No surcharge, ideally, should be permitted for its use.
If you shop for gems during your trip, retain some of your hotel and shopping receipts especially for gems. That will make customs clearance easy. Visitors bringing in excess US$ 10,000 or equivalent should declare the amount to Customs. All unspent money, which was converted from foreign currencies declared on arrival, can be re-converted to original currency. You are required to produce encashment receipts.