We have provided sample letters that you can use to request waivers of several different types of IRS penalties. A penalty abatement request letter asks the IRS to remove a penalty for reasonable cause and contains an explanation of your circumstances.Requests for a penalty waiver must be in writing. Penalty may be waived on an assessment if you can show reasonable cause for your failure to pay on time. Use Form 843 to claim a refund or request an abatement of certain taxes, penalties, additions to tax, interest, and fees. The IRS can waive penalties if you demonstrate that your failure to comply with tax requirements was due to reasonable cause. Taxpayers can request relief from penalties. For the failure to file or pay penalty, taxpayers can request that the IRS "abate" the penalties.