Be careful with 5000 colon and 10 000 colon bills, which are being reproduced by hi-tech gangs who are being targeted by authorities.  The gangs operate out of homes using a computer, scanner and printer to produce the false bills.

Chief Fraud Investigator Randall Zamora, of the OIJ, stated that "it is hard to say how many people are affected monthly, because victims are too embarrassed, or just try to pass it along to someone else".  A person who does this can be sanctioned with a fine equivalent to 30 to 150 days jail time.

The fake bills are pretty realistic and can even be passed through banks, which will exchange the bill if it can be proven from video tapes that it was received from a cashier or ATM.  However Costa Rican currency has several security features that can help you detect a fake bill.

UV markings: shops sell portable or fixed ultraviolet lamps that show flourescent markings present on bills.  Also there are markers that mark yellow on a good bill, but brown on a counterfiet.

Shiny Sheen: On the face of the 5k  & 10k bills, there is a band on the right hand side that reflects a silvery or pinkish metallic depending on the light.  Also bills that are newer than 1999 have a silver band on the left hand side.

Watermark: Every bill has a water mark that is only visible when held up to daylight.  2000 is a hammerhead shark, 5000 has a tucan, and the 10000 has the bust of Emma Gamboa (whose face appears on the front. )

Water: If the counterfeiter used an ink jet printer the ink will run when wet! (not 100% effective, because they probably would use a laser printer or possibly waterproof paper or inks)