The average cost of hiring a private investigator is $50 an hour. This may vary from state to state and the type of services required. Additional charges, such as gas mileage of roughly $0.45 a mile, may apply as well.
Flat fees may be charged for simpler investigative services, such as research, background checks and criminal record searches. The more difficult the investigation, the higher the fees. Most private investigators require an up-front deposit depending on specific factors. Some of these include how much travel is required or how long surveillance may take. Regardless of the service, most private investigators keep an itemized record of what they do for a client to justify each cost.