Topic no. 653, IRS notices and bills, penalties and interest charges
Typically, interest is added to any unpaid taxes starting from the original due date of the return (without extensions) until the full payment is made. The ...

Making IRS payments: What occurs if you owe taxes?
The response is affirmative; it's crucial to file your return or an extension to avoid the penalty for failing to file. This penalty amounts to 5% of the unpaid balance ...

Tax Time Guide: Utilize IRS electronic payment methods for quick and secure ...
Individuals need to settle any taxes owed by April 15, irrespective of an extension to file a return not related to disaster relief. Interest and late fees ...