By Cole Lauterbach/Illinois Radio Network

SPRINGFIELD – Illinoisans scrambling to prepay their property tax bills this week may be doing it for nothing, according to the IRS.

In an opinion released Wednesday, the Internal Revenue Service is warning property taxpayers that they may not be able to get the full deduction of their local tax on their federal returns by prepaying before the new year.

The biggest caveat to whether the new $10,000 cap will be applied to an early property tax payment is whether the local assessor has given their valuation of the property in question. If the assessment doesn’t happen until 2018, the IRS says they’re going to cap the deduction at $10,000.

In a release, the IRS says “a prepayment of anticipated real property taxes that have not been assessed prior to 2018 are not deductible in 2017.”

Some township assessors will not send out assessments for months, which would make the prepaid property tax bills over $10,000 only partially deductible..

In Will and DuPage counties, people have crowded into their respective treasurer’s offices in an effort to skirt the new law. Counties differ on how much they allow in prepayment. Cook County allows only 55 percent of next year’s bill to be paid early. Will County allows for up to two years of prepayment. DuPage allows 105 percent of the previous year’s assessment.

For more information, go to irs.gov or contact a tax professional.