Form 843 (Request for Tax Adjustment/Claim for Refund) is a document filed with the Internal Revenue Service (IRS) when a taxpayer needs to request a refund of certain taxes or abatement of interest or penalties applied in error.

Filing Form 843 is the only way to request a refund or adjustment of certain taxes. This form can apply to many different types of taxes, such as income tax, self-employment tax, and employment taxes. It can also be used to claim relief from interest and penalties related to previously assessed taxes.

In order for a claim to be considered for refunding or adjusting taxes, Form 843 must be filed within two years from the date taxes were paid, or three years from the date when the return was filed (whichever is later). It is important to note that separate forms must be filed for each type of tax or fee, and for each different tax year.

In general, the IRS will not issue refunds unless the taxpayer has a valid reason for it. The specific reason for requesting a refund must be listed on the form. In some cases, the taxpayer may need to provide proof that the funds were mistakenly paid or assessed.

Form 843 must be complete and include accurate and complete information in order for any adjustment or refund claim to be accepted and processed. Any inaccurate information or omission of required financial data can result in delay or denial of the claim.

If a taxpayer requests a refund, the form must include all relevant information related to the IRS account, including the taxpayer's social security number or employer identification number (EIN), the tax return period or accounting period, and the amount of the refund that is being requested. If a taxpayer requests abatement of interest or penalties, the form must include all relevant information related to the IRS account, including the taxpayer’s social security number or employer identification number (EIN), the tax return period or accounting period, the reason for the abatement, and any additional information supporting the request.

Form 843 provides an effective route for taxpayers to correct any overly-assessed taxes, or a request for a refund of mistakenly paid taxes. Taxpayers should familiarize themselves with the form's requirements and process to ensure that their request is properly filed.