If you have a balance due and don’t file a tax return by April 15, you face interest on the unpaid taxes as well as a failure-to-file penalty. Interest and penalties are added to your balance due. If you can’t file by the deadline, request an extension of time to file (see below).

If you file on time or request an extension but don’t pay all or some of the balance due by the deadline, you will incur interest on the unpaid amount and a failure-to-pay penalty. If you can’t pay the full amount, you should pay as much as possible by the deadline to minimize interest and penalties. Read more …