Posted On April 01, 2017

Math errors and other mistakes: When do you have to amend your return?

To err is of course human – and that certainly includes errors on tax returns.

If it turns out that you made a math miscalculation or some other mistake, what happens then? Is it necessary to amend your return?

The short answer is that it depends on what type of mistake is involved.

Let’s start with the question of mathematical errors. In 2014, the IRS found more than two million such errors. The IRS generally fixes them when processing returns. It isn’t necessary to amend your return to correct them.

There are, however, other mistakes that can delay processing of your return or cause the IRS to reject it. Having a missing or incorrect Social Security number or incorrect name can make it difficult for the IRS to match income reported on your return with information from employers, banks and other third-party sources.

This can easily happen to women who are newlyweds, if they take their husband’s name. If you are in that situation, be sure to communicate with the Social Security Administration (SSA) to make sure SSA is aware of the name change.

When amending a return is needed

The circumstances in which amending a tax return is in order concern changes in income, credits, deductions or filing status.

After filing your taxes, you may become aware, for example, that you are eligible for a credit or deduction you didn’t know about before. Amending a return to take advantage of this new information is a common occurrence.

But there is a very specific procedure needed to do this. Amending a return has to be done through a paper form, Form 1040X. It can’t be done electronically.

Finally, we should note that if you are running out of time and haven’t filed your return, it’s a mistake not to file an automatic extension. The form for that is Form 4868.