The best method of identifying a possible counterfeit check is by looking at the reasons on why the check was received in the first place. Strangers don't send checks for thousands of dollars to other strangers for no reason. If a check recipient is asked to send part of the check proceeds back to the stranger for any reason, there is a 99.9% chance that the check is a counterfeit item. Mystery shopper programs, sweepstakes and lottery contests, inheritance gifts from long lost (and unknown) relatives, payroll processing job offers using a consumer's personal account, and Internet sales where the buyer sends more than is needed for the purchase price are all examples of scams involving counterfeit checks.
Victims of these scams often say later that they had a bad or uneasy feeling about the fake checks being negotiated. They convince themselves though that the official check and overnight mail package could only have come from a "legitimate" entity. These same victims also refer to official looking websites and mail correspondence that looks like the real thing. Criminals can copy and reproduce anything. They try to build confidence in the victim's mind that the offer being presented is the real deal. Sadly, greed is also a contributing factor to many of these fake check scams as the victims are promised easy money for their efforts.
Don't be a victim. Ask your credit union or financial institution to research the item and be sure to provide all information about how the check was received. Depositing a counterfeit check item is a crime so be sure that all check items are legitimate BEFORE they are deposited.
The website below provides excellent resources and information regarding fake check scams;