• The return itself is not complete.
• Required schedules are either incomplete or missing.
• Failure to write legibly when making letter and number entries. (Use black ink and all CAPITAL letters)
• Failure to double check math computations.
• Failure to round cents to the nearest whole dollar. (Enter whole dollar amounts only)
• Failure to enter your complete and or correct Social Security number.
• Failure to indicate the filing status in the personal information section of the return.
• Line 10 on the District form D-40 is not a total of lines 3 through 9 on that form. It is for entering the figure that you entered on line 22 of your Federal form 1040.
• While you may take either itemized deductions or the standard deduction, you must, on your District tax return, take the same type deduction as the one taken on your federal tax return.
• Use DC Schedule J to figure your tax only if you are filing Married Filing Separately on the same return.
• Failure to enter on the Schedule S form your dependent(s)' information - name, Social Security number and relationship to you.
• Failure to sign the tax return. Both signatures are required when filing jointly.
• Failure to staple required items to your tax return. Staple the following items to your tax return in the order and location shown in the D-40 instructions:
  

  	Forms W-2 - Wage and Tax Statement
  	Forms 1099 R - Distribution from Pension, Annuities, Retirement, etc.
  	Payment of tax due - made payable to "DC Treasurer"
  	A copy of each required federal schedule (Schedule A, C, D, etc.)
  	A copy of your completed state return when claiming an out-of-state credit on your District return

• Failure to include on your tax payment your Social Security number, the tax year and the number of the form you are filing.
• Make sure that you receive written confirmation from the tax preparer that your electronically filed DC return was accepted.
• Failure to complete your return so that we know whether there is an additional tax liability, a refund due or that the tax due has been paid in full.
• If you are not filing your Individual Income or Fiduciary tax return by the April 15 due date - form FR-127 Extension of Time to File must be filed by the April 15 due date. You must complete the form FR-127 and pay the full amount of tax due. Penalty and interest charges may be assessed if the payment accompanying the extension request is less than the amount of tax due when you actually file your return.

	Include the square, suffix and lot numbers if you own the real property for which you are claiming the credit;
	Include your landlord's name, address and telephone number and the dollar amount of your rent for the year if claiming the credit based on rent paid;
	Report income earned by all those living in your household. Also report their names, Social Security numbers and telephone numbers; and
	Include a completed and signed physician's certificate when claiming a credit for blindness or disability.