PHILADELPHIA (CBS) — Are you thinking about hiring someone to do some work around your house? With spring just around the corner, the New Jersey Attorney General’s office is reminding consumers to beware of unregistered contractors. 3-On Your Side Consumer Reporter Jim Donovan went along as state investigators issued warnings to home improvement contractors – comply with the law or face a big fine.

This pick-up truck looks like the rest of the trucks in this Home Depot parking lot but inside are state investigators scouting for contractors who are violating the law. Supervising Investigator Andrew Tucker says, “Contractors need to know when they are doing home improvement work in the state they need to be registered, and abide by the law.”

Over the past few days undercover investigators from the Attorney General’s office issued dozens of warnings to contractors who advertise home improvement services, but fail to display a state registration number on their vehicles. Tucker says, “We are trying to first get the message out first with a warning and give a 30 day turn around time.”

In New Jersey, home improvement contractor registration numbers begin with 13VH. Contractors who don’t post the number on vehicles or those who are found not to be registered at all face up to a $10,000 fine. Last year 32 contractors were fined a total of $189,000 by the state.

“This is a law five years along and we have a lot of contractors in the state that are thumbing their nose at it,” says Hal Spence, Director of Gloucester County’s Consumer Protection Office.

Spence believes the state crackdown will send a message to unregistered contractors. He says, “Mostly it’s contractors that will come, start a job and leave, take their money and leave.”

Contractor Mike Ford is registered with the state but didn’t know that he had to post his number on his truck. But he’s glad to hear about the crack down too. Ford says, “It will be helping the guys that have been paying insurance all of these years the right way and the guys that ain’t, they’re going to go after them.”

All of the contractors that were issued warnings did violate the rules in terms of signage. Investigators will now be checking to see if they are indeed registered with the state or not.

Home improvement contractors include everyone from roofers and painters to carpenters and landscapers. That 13VH registration number must be on the contractor’s truck, contracts, and advertising.

To check the list of registered contractors in New Jersey before you hire someone visit the link below:

Home Improvement Contractor Registry

Reported by Jim Donovan, CBS 3