I:8-67 Mark Hancock is a self-employed attorney who operates his law practice as an unincorporated sole proprietorship. In 2020, the IRS disallowed several business deductions he took in 2018 and 2019. In addition to paying the deficiency and assessed penalties, he also pays $18,000 in interest on the tax owed. Can he deduct that interest in the current year?

• Sec. 162, Sec. 163

• Reg. Sec. 1.163-9T

• Kikalos v. Comm., 84 AFTR 2d 99-5933