A computer glitch has caused a delay in mailing property tax bills to about 6,000 property owners in Middletown and Trenton, according to the Butler County treasurer.

About four percent of the 144,876 bills to be mailed on Jan. 31 did not go out because a data file containing the information was corrupted and not transmitted electronically to the contractor that prints and mails the documents, Treasurer Nancy Nix said. The bills were scheduled to go into the mail Thursday or today, she said.

“It was a fluke thing that can happen when dealing with electronic data,” Nix said. “We will never know exactly how it happened.”

Nix said the problem came to light when her office began receiving calls from residents who did not get their tax bills.

By law, the treasurer’s office must send out bills 20 day before they are due. Nix said they always leave a cushion just in case there are problems. Payments are due by Feb. 28, so the office is still in compliance.

Bills can also be viewed online at “View my tax bill” on the treasurer’s website: www.butlercountytreasurer.org. Payments can also be made through the site.

Valuations can be contested with the Board of Revision through the county auditor’s office by March 31.

According to Ohio law, a late payment penalty of “½ of 10 percent” will be charged against past due current year taxes, provided that the balance due is paid in full within the first 10 days following the due date. Otherwise, a full 10 percent penalty will be charged.

Interest will be charged against the remaining unpaid balance for prior tax years on the first day of the month following the second half due date. Interest will be charged on the total unpaid balance on Dec. 1.