The practice is known as PIN slamming, and involves two Property Index Numbers to be linked to one home. It may not always be disclosed in closing documents.
"It's rough, but I work so much that I can try and compensate, but it keeps me in the hole constantly," said Irving Myrick, homeowner.
Myrick says the slam is doubling his property taxes from about $5,500 a year to $11,000 a year.
"It's actually the worst PIN slamming to date that our office has ever seen," said Mario Reed, Cook County Recorder of Deeds fraud investigator.
The I-Team brought Myrick's case and others to Reed.
"In order for him not to lose the house he is going to be slammed with over $26,000 worth of taxes," Reed said.
It can happen anywhere, but county leaders said decades ago in one Markham neighborhood developers built homes sitting on two lots. Because of that, when some residents get their tax bills they discover their annual property taxes are double what they expected. Some pay anywhere from $6,000 to $12,000 a year for homes valued under $200,000.
"I was just shocked," said homeowner Ouida Jones. "I found out at the very last moment and had to calm down, because I really wanted the house."
USEFUL LINKS: Look up your PIN to find out if you have hidden property taxes
Cook County Assessor
Lake County Chief County Assessment Office
McHenry County Treasurer's Office PIN Search
Kane County Treasurer's PIN Search
Will County PIN Search
County of DuPage PIN Search
Jones is Myrick's next door neighbor.
"I don't wat to lose my home. I do not want to lose my home," she said.
Her real estate attorneys and title company told her about the two PINs in advance, but she said she didn't realize her taxes would be $12,000 a year until she was at the closing. But she still chose not to pull out of the purchase.
"Because all the money that was invested, and then the thought that okay, maybe this--really, I was hoping maybe it was a mistake," she said.
The listing for the home shows the taxes to be about $6,000 with one PIN. PNC Bank, which sold her the home, said it is "committed to responsible business practices. We looked into this and we started putting additional controls in place to ensure the real estate brokers we work with are disclosing pins appropriately."
"So I'm being doubled counted, double-dinged for this home," Jones said.
"I was more than surprised, because I put my life savings into this house," said Calvin Hodges, homeowner.
Calvin and Juanita Hodges live just down the block and are also struggling.
"When you are retired and on a fixed income, it does not come easy," Calvin said.
Their annual tax bill is about $6,500 a year for two PINs instead of $3,275 a year for one.
"The Hodges were absolutely PIN slammed," Reed said.
"Then I received notice from the county sheriff delivering a paper saying my house was being sold for back taxes, a PIN I didn't even know about," Calvin said.
"So the seller definitely has to tell you if there are two PINs. If the seller knows - in certain circumstances they may not know if it is not the original developer," said Reed.
Michael Moncao, the developer who sold the Hodges their home, had two PINs on his warranty deed, but said he thought they'd been committed to one parcel of land, and that the one PIN on the contract matched the title search. Monaco also said he's helping the Hodges to file a claim with their title insurance company.
As for Myrick, the Recorder of Deeds' office said that First Merit Bank also recorded a foreclosure deed with two PINs but sold it to him with one. The bank did not get back to the I-Team.
"I mean, these poor people. I think ABC 7 is doing a service telling people when you buy a house, ask these questions," said Tom Shaer, Cook County Assessor's Office.
The Cook County Assessor's Office said title insurance companies should be held responsible.
"A title company should find a number of things, the easiest is multiple PIN numbers. It's not unusual for a house to have two PINs and you can find it easily downloaded from the assessor's website. It took me about four minutes. The title company should find a number of things, the easiest of which is multiple PIN numbers," Shaer said.
Hodges used Chicago Title Insurance Company, which did not get back to the I-Team. Greater Illinois Title Company, which covers Myrick, said a "land property survey was not furnished by the buyer or the seller," and said they knew of a discrepancy in 2015 but a claim was never filed.
"(The title companies) are in a position to examine and determine if there are multiple pins," said Frank Pelligrini, member and former president of the American Land Title Association and the Illinois Land Title Association. "However, having said that there are instances where the property description is complicated and sometimes that extra PIN might slip by."
He said everyone involved in the deal should take some of the blame.
"You can't trust the seller, you can't trust the title companies, ultimately you really have to trust your attorney and yourself for assuring you are protected," he said.
I have to do extra things to compensate for one piece of property that I shouldn't be paying for, but I am paying for two," Myrick said.
Homeowners may also be able to appeal their assessment to reduce their tax bills.
You should always ask your real estate attorney to order a Plat of Survey to spot multiple PINs.
CLICK HERE for more things you should know before you buy a house.