Don’t panic. If you cannot pay the full amount of taxes you owe, you should still file your return by the deadline and pay as much as you can to avoid penalties and interest. You also should contact the IRS to discuss your payment options at 1-800-829-1040. The agency may be able to provide some relief such as a short-term extension to pay, an installment agreement or an offer in compromise. In some cases, the agency may be able to waive penalties. However, the agency is unable to waive interest charges which accrue on unpaid tax bills.