BOSTON – Massachusetts’ tax collections came in at $1.969 billion – $87 million less than projected – last month, the Mass. Department of Revenue said.

In a news release, the department last week attributed the shortfall to income tax collections, which came in $93 million below the department’s estimates. Sales tax came in above projects, while corporate taxes also failed to reach their benchmark.

However, “there is no certain explanation for the shortfall,” the department said in the release.

The department said that December and January need to be viewed as a whole when it comes to cash-estimated payments, particularly this year. There were two fewer December deposit days than a year ago, and the final deposit day fell on a holiday weekend, the department said. Some of the payments may be pushed into January.

Overall, revenue of $9.847 billion for the first half of fiscal 2012 finished $252 million ahead of a year ago, an increase of 2.6 percent, and $49 million below the revised fiscal 2012 benchmark of $21.010 billion. •