TWIN FALLS, Idaho (KLIX) – If you received an automatic extension to file your Idaho tax return, time is running out to send your return and full payment. The deadline is Monday, Oct. 17.

“We expect about 32,000 individual income tax returns to be filed,” said Chris Barry, central processing bureau chief for the Tax Commission.

Idaho law allows these taxpayers to avoid a penalty for late filing, according to the Idaho State Tax Commission, but they’ll be charged 4 percent interest on any tax that was due and not paid by April 18.

Filers can pay their taxes electronically. Or they can mail returns and payments to the Idaho State Tax Commission, P.O. Box 56, Boise, ID 83756-0056.

Some may qualify to file online for free. For help computing interest, taxpayers should call (800) 972-7660 or visit a Tax Commission office.