Can I Spend UAE Dirhams in Bahrain and Oman?
The quick answer is that you won’t be able to really spend Dirhams in Oman and Bahrain, which both have their own currencies. It is likely, however, that you would find some shops willing to take UAE Dirhams. However, since currency exchanges are all over the place in Oman, Bahrain and the UAE you should just exchange your money into the local currency (not too much though) and then you won’t have any problems. Your hotel would be able to change more money for you if you do run out. The website below has information on all three countries, their currency rates, and general travel tips as well.
In Oman they do take UAE money at some places. In UAE GCC Currencies are acceptable at places like Carrefour hypermarket. I am not sure about Bahrain , though Carrefour has branches in most gulf countries, I am not aware of one in Bahrain. see website http://www.carrefouruae.com/ they do have a Geant however http://www.geant-bahrain.com/ By the way ATM cards work across GCC so that may be a better option as you will get the cash in the currency where you are. You can also use credit cards or pre-paid Visa cash cards. Checks are not acceptable.