1040X Instructions for Dummies

1040X Instructions for Dummies
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With all the numbers and regulations taxpayers use to calculate tax owed or refunds expected, it is reasonable to expect the IRS to allow for errors. This allowance is the thinking behind the IRS Form 1040X.

Do I Need to File?

One of the first 1040x instructions for dummies is to figure out if you need to fill the form out at all. If you are correcting a simple number error, addition or subtraction error, or other fundamental mistake, you do not need to file a corrected return. The IRS will notify you that they caught it. If the mistake causes an underreporting or overreporting of taxes due, then you do need to file a 1040X. Doing so ahead of notification from the IRS can save interest penalties and other fees. According to H&R Block, you can file a 1040X for taxes filed up to three years prior to the current year.

The Forms

To use the 1040X, you must have originally used one of the other forms in the 1040 series. These include the 1040, 1040A, 1040EZ, 1040EZ-T, 1040NR, and the 1040NR-EZ. If you did not use any of these forms, you cannot use the 1040X for corrections. You will need one copy of the IRS Form 1040x and the accompanying 1040x Instructions. You will need a fresh copy of the 1040 form you filed. You will need the copy of your original 1040 form. You may also need the supporting documents used if you have lots of errors to fix. Gather all of these things up and sit down at a table.

General Line Instructions

An important part of the 1040X instructions for dummies is to read page 5 of the instruction booklet. This page provides general guidance for basic corrections and shows you which lines on the form you must pay attention to.

List the year you are amending in the section above your name. This tells the IRS which year to look for. List the social security numbers in the exact order you used on the original return.

Always fill out the top of Page 1 on the 1040X down to “Amended Return Filing Status” regardless of what you are changing.

Use the instructions from the original 1040 series form and correct year to ensure you use the right calculations for tax. Since IRS rules seem to change yearly having the correct instructions for the year you are amending is important.

If you are changing numbers or math on your 1040X, you want to use the quick guide on page 6 of the instruction booklet. This guide tells you specifically what lines will be filled out on your 1040X when you are changing numbers on certain lines from your original return.

If you are not changing anything, but wish to add something, most of the form is irrelevant. Fill in the areas for the filing year, personal identification, and if you want to support the Presidential Election Fund. Then, go straight to Part III of the form. Part III is the explanation of the changes you are creating.


You will need to file a 1040X for each year you are amending. You will also need all the forms and supporting documents for each year you are amending. According to the IRS, if you are seeking a refund for taxes or penalties already paid, you must use Form 843 instead of 1040X.


Another important area within the 1040X instructions for dummies is Part I found on page two of the form. This is where changes in exemptions are handled. Only use this section if you are increasing or decreasing the number of exemptions or the value of the exemptions.

Column Arrangement

The columns on the right of page 1 of your 1040X are used for changing figures. Column A is where you enter the original numbers, or IRS adjusted numbers.. Column B is where you enter the new corrected numbers for that line. Column C is the difference either positive or negative. If there is no change in a line, enter the amount in Column C and continue. Column C must be complete to finish the calculations at the end.

Explaining the Changes

The IRS will want to know why you are amending a return. Attach any supporting documents or schedules to the back of your 1040X. There are 13 lines you can use in this box. Explain fully and thoroughly without using extra wording. Keep to the facts. Let the supporting documents tell most of the story or provide the evidence.


While the IRS doesn’t make 1040X instructions for dummies, understanding those instructions does not need to be difficult either. Simply stop and read over pages 5 and 6 to understand the basic components of the form. Remember that the 1040X is for correction purposes. You don’t need to recreate an entire original form. Make sure you have someone familiar with tax issues look over the revised numbers.


Internal Revenue Service

H&R Block

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