Investment advisory fees. 

Fees for investment advice, including any related services that would be provided to any individual investor as part of an investment advisory fee, are incurred commonly or customarily by a hypothetical individual investor and are not deductible. However, certain incremental costs of investment advice beyond the amount that would normally be charged to an individual investor are deductible.

An incremental cost is a special, additional charge that is added solely because the investment advice is rendered to a trust or estate rather than to an individual, including balancing beyond the usual varying interests of current beneficiaries and remaindermen. The deductible portion of the investment advisory fees is limited to the amount of those fees, if any, that exceeds the fees normally charged to an individual investor. See Regulations section 1.67-4(b)(4).