Calculation of Excise Tax

[Guest MJ1]

The interest is the greater of the actual interest or a market rate of interest. For the latter, do we use prime plus 2% (as suggested in the IRM), or can we use the 6621(a) underpayment rate?

[Guest sheTexasHammer]

The interest is the greater of the actual interest or a market rate of interest. For the latter, do we use prime plus 2% (as suggested in the IRM), or can we use the 6621(a) underpayment rate?

In a recent phone forum given by the IRS on the topic of excise tax returns, the IRS stated that the 6621(a) rate was a proper rate to use in calculating the excise tax returns.