If you disagree, contact the IRS at the toll-free number listed on the top right corner of your notice or respond by mail to the address on your notice. If you write to the IRS, include a copy of the notice along with your correspondence or documentation.
If you contact the IRS within 60 days of the date of this notice, they may reverse the change made to your account. You don’t need to provide an explanation or additional documents when you request the reversal, but the IRS will consider any information you provide. However, if you can’t provide additional information that justifies the reversal and the IRS believes the reversal is in error, the IRS will forward your case to the Examination department for a formal review of the items in question. Forwarding your case gives you formal appeal rights, including the right to appeal the IRS decision in court. After the IRS forwards your case, you should be contacted by a member of the Examination staff within five to six weeks to explain the audit process and your rights.
If you don’t contact IRS within the 60-day period, changes made to reduce your refund will not be reversed. Instead, you may file a claim for refund to dispute the changes. Generally, you must submit the claim within 3 years from the date you filed the tax return, or within 2 years from the date of your last payment for this tax, whichever is later.
If you don’t contact the IRS within the 60-day period, you’ll lose your right to appeal their decision before payment of tax. After 60 days, reversal requests must be substantiated.