IRS Form 945-X, Adjusted Annual Return of Withheld Federal Income Tax or Claim for Refund is a form, used to correct administrative errors on previously filed IRS Form 945. An administrative error occurs when the reported amount of withheld income tax differs from the actual amount. The most recent version of this form was issued by the Internal Revenue Service (IRS) in February 2014. A fillable Form 945-X is available for download below.
The form should be filed as soon as possible after the moment the mistake was discovered. The due date depends on the type of mistake, whether the taxes are over-reported or under-reported. Overreported taxes can be corrected within three years since IRS Form 945 was filed or within 2 years since the reported tax was paid, whichever is later. Under-reported taxes can be corrected within 3 years after Form 945 was filed. If it is necessary to correct returns for several years, a separate IRS 945-X Form should be filed for each year.
If Form 945-X due date falls on Saturday, Sunday or a legal holiday, the form can be filed on the next business day. But if the envelope containing the form is properly addressed, postmarked by the U.S. Postal Service before or on the due date, and contains sufficient postage, the form will be treated as filed on time.