According to several media sources there are counterfeits of current high denomination notes that may fool banknote acceptor machines. It seems that current notes may be split in two sides, after which a forged other side is pasted on it. When the forged note is checked the machine will recognize the real side as genuine. So far most of these counterfeits are of 10,000 (CRC 10,000.2) and 20,000 colones notes (CRC 20,000.1). 

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