The IRS can waive penalties if you demonstrate that your failure to comply with tax requirements was due to reasonable cause. We have provided sample letters that you can use to request waivers of several different types of IRS penalties.You may qualify for penalty relief if you tried to comply with tax laws but were unable due to circumstances beyond your control. How to Apply for Reasonable Cause IRS Penalty Abatement. You must complete IRS Form 843 – Claim for Refund and Request for Abatement. This guide provides a sample letter to IRS to waive penalty which will help you present your case and request relief from penalties.