ITHACA, N.Y. -- Counterfeit cash has become a problem in Tompkins County. The Ithaca Police Department says it has seen an increase of bogus bills being used in the city.

One hundred dollar bills have been the most common problem. Detectives say counterfeit currency is seen more often during the holidays as people struggle to make ends meet. Sometimes busy cashiers don't notice that they're fake.

Police detectives want to hear from anyone who’s run into the counterfeit currency.

The Secret Service has a list of tips to protect yourself from the phony cash. Experts say you should compare genuine bills with suspect ones. Check the seals and borders as sometimes you can see differences in color and check the paper it’s printed on. Genuine currency paper has tiny red and blue fibers embedded throughout.

To see the full list of Secret Service tips, visit www.secretservice.gov