Penalties shall be waived upon a determination of reasonable cause. Reasonable cause shall include, but not be limited to, those instances.You must provide a valid explanation of the reason you are requesting a waiver. Your account will be reviewed, and an agent will reply back to you. Penalty Waiver Form. We have provided sample letters that you can use to request waivers of several different types of IRS penalties. This guide provides a sample letter to IRS to waive penalty which will help you present your case and request relief from penalties. What if I did not receive a tax statement and my account goes delinquent? Will I still have to pay penalties?