Mississippi tax collections were $46 million, or 8.2 percent, below the estimate for the month of April.
Kathy Waterbury, a spokeswoman for the state Department of Revenue said the agency thinks the majority of drop may be due to timing of receipts/processing.
She says the agency won't know for certain until all of the income tax mail is opened and processed, which should occur this month.
Waterbury says individual income tax collections came in at $65.7 million, or nearly 27 percent, below the estimate for the month.
The loss was offset in part because of better-than-anticipated collections of corporate income taxes, sales taxes and insurance premium taxes during April.
Tax collections are $92.5 million above the estimate for the fiscal year, which ends June 30.