The IRS last week reported that underpayment interest rates for Q4, would remain the same at 3% for business that owe less than $10k and 6% for large corporations that owe more than $10,000. The IRS calculates underpayment interest rates by taking the short-term federal rate (around 1% rounded) plus whatever your current business status is with payments. If you owe less than $10k, your interest rate will be 3%, whereas large corporate underpayments would be charged 6% percent a month.

If your business is caught owing the IRS, realize it is in your best interest to come forward with the IRS as they face declining tax revenues. Waiting to resolve an IRS problem such as unpaid taxes, a tax lien, or notice of a levy will only lead to more penalties, interest, and issues down the road.