Interest, compounded daily, is charged on any unpaid tax from the due date of the return until the date of payment. The interest rate is the federal short-term rate plus 3 percent. That rate is determined every three months.

For current interest rates, go to News Releases and Fact Sheets and find the most recent Internal Revenue release entitled Quarterly Interest Rates.

In addition, if you filed on time but didn't pay on time, you'll generally have to pay a late payment penalty of one-half of one percent of the tax (0.5%) owed for each month, or part of a month, that the tax remains unpaid after the due date, not exceeding 25 percent. However, you will not have to pay the penalty if you can show reasonable cause for the failure. The one-half of one percent rate increases to one percent if the tax remains unpaid after several bills have been sent to you and the IRS issues a notice of intent to levy.

Beginning January 1, 2000, if you filed a timely return and are paying your tax pursuant to an installment agreement, the penalty is one-quarter of one percent for each month, or part of a month, that the installment agreement is in effect.

If you did not file on time and owe tax, you may owe an additional penalty for failure to file unless you can show reasonable cause. The combined penalty is 5 percent (4.5% late filing, 0.5% late payment) for each month, or part of a month, that your return was late, up to 25%. The late filing penalty applies to the net amount due, which is the tax shown on your return and any additional tax found to be due, as reduced by any credits for withholding and estimated tax and any timely payments made with the return. After five months, if you still have not paid, the 0.5% failure-to-pay penalty continues to run, up to 25%, until the tax is paid. Thus, the total penalty for failure to file and pay can be 47.5% (22.5% late filing, 25% late payment) of the tax owed. Also, if your return was over 60 days late, the minimum failure-to-file penalty is the smaller of $100 or 100% of the tax required to be shown on the return.

Also, refer to Tax Topic 653, IRS Notices and Bills and Penalty and Interest Charges.

References:

• Tax Topic 653, IRS notices and bills and penalty and interest charges
• News Releases and Fact Sheets

Your return must be postmarked by June 15th.

References:

• Publication 17, Your Federal Income Tax
• Form 4868 (PDF), Application for Automatic Extension of Time to File U.S. Individual Income Tax Return

Yes, an employer may furnish your Form W-2 (PDF) electronically provided certain criteria are met. You must affirmatively consent to receive the Form W-2 (PDF) in an electronic format and prior to, or at the time of, your consent, your employer must provide you a disclosure statement containing specific disclosures. Additionally, the electronic version of the Form W-2 (PDF) must contain all required information and comply with applicable revenue procedures relating to substitute statements to recipients. If the statement is furnished on a Web site, then your employer must notify you, via mail, electronic mail, or in person, that the statement is posted on a Web site and provide instructions on accessing and printing the statement.

References:

• Treas. Reg. 31.6051-1(j)

Your first estimated tax payment is usually due the 15th of April. You may pay the entire year's estimated tax at that time, or you may pay your estimated tax in four payments. The four payments are due April 15th, June 15th, September 15, and January 15th of the following year.

If the due date for making an estimated tax payment falls on a Saturday, Sunday, or legal holiday, the payment will be on time if you make it on the next day that is not a Saturday, Sunday, or legal holiday.

References:

• Publication 505, Tax Withholding and Estimated Tax, Chapter 2.

Some forms and entities have due dates other than the well-known April 15th due date. The instructions for the each type of form used will have the appropriate due date(s) noted. In general, sole proprietor's schedule of income and expenses is attached to the Form 1040 (PDF). Therefore, the due date is the same as the Form 1040 (PDF).

A Corporation may use either the calendar year, or a different tax year. An S corporation generally must use the calendar year, unless the entity can establish a business purpose for having a different tax year. The due date is March 15th for corporations on a calendar year and the 15th day of the third month following the end of the tax year for other corporations.

A partnership generally must conform its tax year of the partners unless the partnership can establish a business purpose for having a different tax year.

References:

• Publication 541, Partnerships
• Publication 542, Corporation
• Publication 334, Tax Guide for Small Business
• Entities: Sole Proprietor, Partnership, Limited Liability Company/Partnership (LLC/LLP), Corporation, Subchapter S Corporation

Yes, you can electronically file your return after April 15th. Electronically filed tax returns are accepted until October 15th. However, for your return to be considered timely after April 15, you must file Form 4868 (PDF), Application for Automatic Extension of Time to File, on or before April 15th. If April 15th falls on a weekend or federal holiday, you have until midnight the following business day to submit your extension request or your tax return. With a timely filed extension request, you have until October 15th to timely file your return. If an extension of time to file has not been timely submitted you may be subject to a failure to file penalty if you file your return after April 15th.

References:

• Tax Topic 304, Extension of Time to File Your Tax Return
• Electronic Services
• Form 4868 (PDF), Application for Automatic Extension of Time to File US Individual Income Tax Return