TOPEKA — State officials pinned a December spike in tax collections on changes to federal income tax policy, the Kansas Department of Revenue announced Tuesday.

Kansas tax revenue beat estimates last month by $83.6 million, or 6.5 percent, according to the release. Most of that was driven by high individual income tax collections.

According to the release, the new federal plan that caps state and local tax deductions drove some filers to make payments before the end of 2017.

“This is simply a shift in the timing of tax payments,” Revenue Secretary Sam Williams said in the release. “We truly will not know the effect of state and federal tax policy until after the filing deadline in April.”

Kansas tax collections have beat estimates each month since the Legislature’s tax increase went into effect July 1. In November, estimators met and nudged their tax collection expectations upward, but said they were cautious in their predictions.

Budget Director Shawn Sullivan said at the November meeting individual income taxes are difficult to predict because the Legislature’s plan returns filers whose pass-through income had not been taxed to the rolls. It’s unclear when those filers might begin making payments.