In addition to the sticker shock of large tax increases, some taxpayers in northwestern Cook County have found mistakes in the property tax bills they received in recent days.

Some Schaumburg Township residents say they didn't receive their rightful homeowner's exemptions or that their assessments were raised despite an assessment freeze available to some seniors.

It wasn't immediately clear how widespread the problem is or whether it affects other Northwest suburban townships besides Schaumburg.

But Schaumburg Township Assessor John Lawson's office was swamped Thursday and Friday with residents seeking relief.

Though Lawson said these problems occurred at the county level, his office is available to help residents fill out and file certificates of error. That should result in the homeowner receiving an amended tax bill.

The Cook County assessor's office Saturday was unable to verify where any problems may have occurred.

"Anyone who didn't get an exemption that they're entitled to should come to our office or call us so that we can help them," said Cook County assessor's office spokesman Eric Herman.

Some residents have been frustrated by not being able to get through to the township assessor's staff over the phone and the long lines at his office.

Lawson said his staff of three full-time employees has been overwhelmed by complaints but urged people just to come in rather than call, and to be patient as his staff addresses all the problems.

The Schaumburg Township assessor's office is at 1 Illinois Blvd. in Hoffman Estates.

Like most other township assessors' offices, Schaumburg's reopens Monday. Hours are 8:30 a.m. to 5 p.m.

The Cook County assessor's office has closed its satellite office at the Rolling Meadows courthouse. Its offices include the main one in Chicago at 118 N. Clark St. (312-443-7550) and its Skokie location at 5600 W. Old Orchard Road (847-470-7237).

Daily Herald Staff Writer Anna Marie Kukec contributed to this report.