Establish a written policy that outlines employee responsibilities, standards of honesty, and general security procedures and consequences for not following them. Make sure employees read it, understand it, and sign it as a condition of employment. Then enforce it stringently.
Verify past employment and references of all prospective employees. Be suspicious of any unexplained gaps in their work history.
Keep accurate records of cash flow, inventory, equipment, and supplies. Have it checked regularly by someone other than the person responsible for maintaining it.
Limit access to keys, safe combinations, computer codes, and alarm codes. Change locks and access codes whenever an employee is terminated.
Limit the number of persons responsible for a specific cash function. Never have more than one person on each cash register. Make only one person responsible cash drops or deposits if possible.
If internal theft is discovered take action quickly. Contact the law enforcement agency and follow through. It is important that employees understand that theft will not be tolerated.