Filing Deadlines

• The standard filing deadline for federal individual income tax returns is April 15 of the year following the year for which income is being reported. If you request an extension before this deadline, the IRS will grant an automatic six-month extension (until October 15).
  
  

Forms and Filing

• Most taxpayers will use either IRS Form 1040 or IRS Form 1040EZ. Use Form 1040 if you intend to itemize your deductions (see below), and use 1040EZ if you don't. Self-employed taxpayers will need to file quarterly estimated tax returns using IRS Form 1099. You should include copies of your W-2s with your return if you have any. If you mail your return, the specific address IRS varies according to where you live (see Resource). Electronic filing is also available through the IRS website.
  
  

Calculation Process

• Following is a quick formula to simplify the federal individual income tax calculation process:
  
  (Total income) minus (deductions listed in lines 22-35 of Form 1040) = adjusted gross income (AGI).
  
  (AGI) minus (the greater of your standard deduction and your 1040 Schedule A itemized deductions) minus (the product of $3,500 times the number of exemptions you claimed in line 6d) = taxable income.
  
  (Taxable income) times (applicable tax rate from 1040 Instructions tax rate schedule) = tentative total tax.
  
  Total tax = Your AMT (from IRS Form 6251) or your tentative total tax, whichever is greater.
  
  Total tax minus (taxes already withheld) = total tax due.
  
  If your total tax due is less than zero, you are entitled to a tax refund.
  
  

Late Filing

• If you anticipate not being able to file your tax return on time, contact the IRS and get an automatic extension. If your filing deadline has already passed, you may still be able to avoid penalties if you can convince the IRS that there was "reasonable cause" for you failure to file on time. If you file late without reasonable cause, the IRS will assess a penalty of 5 percent of the amount due with your return for every month that you are late, up to a maximum of 25 percent. If you are 60 days late or more, a minimum penalty of $100 or 100 percent of the amount due (whichever is less) will be imposed.
  
  

Amending Your Tax Return

• If you file your tax return and later discover that you have made an error, don't neglect to amend your tax return. If you underpaid, you could end up with a surprise bill from the IRS (including any late penalties), and if you overpaid, you might miss out on a refund. Download IRS Form 1040X from the IRS website and fill it out. Form 1040X asks you to list your original calculations, provide your amended calculations and provide an explanation for your changes. Of course, if you underpaid, then you will need to include any excess amounts due. Remember that if your filing deadline has already passed, penalties may apply.