Avoid Holding Macao Patacas

The Pataca is Macau's official currency.
http://en.wikipedia.org/wiki/Macau_pataca

Unfortunately, you won't want to hold on to it. It is highly unpopular outside Macau. Even in Hong Kong, you will have a hard time changing it into other currencies.

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But it may be too late - if you are already outside Macao with a load of Patacas.

If you are in the Zhuhai area of China, fret not. You might be able to change it. If the banks don't accept it, you can use it to buy something in the shops.

The shopkeeper may redirect you to an illegal money changer if he does not accept your money. Just beware of counterfeit Renminbi notes (especially for 50 and 100 Yuan).

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Otherwise you can ask a Macau friend, or just keep your cash for the next visit to Macau.