People with tax filing extensions must file by Aug. 15.

The Internal Revenue Service reminds people who filled out Form 4868 and sent it to the IRS by the original April 15 deadline, received an automatic four-month filing extension.

Taxpayers are reminded interest is charged on taxes paid after April 15.

Taxpayers unable to finish their returns by Aug. 15, can apply for an additional extension of up to two months, but this is not an automatic extension. Taxpayers must explain why they need extra time, and the IRS will rule on whether to approve the request.

Additional information on extensions and payment is available by calling 1-800-TAX-FORM