Private foundations are entities that are established for philanthropic, educational or religious purposes. These organizations are generally funded by a single individual or family, and are not required to pay taxes on their income. 

The IRS imposes a 2% excise tax on any self-dealing activities that are conducted by private foundations. Self-dealing is defined as any transaction between a private foundation and a disqualified person in which the disqualified person has a direct or indirect financial benefit. 

Private client tax solutions are required to pay an excise tax on their net investment income. This includes income from interest, dividends, rents, royalties, and capital gains. The rate of the excise tax is 1 or 2%, depending on the amount of the foundation's assets and income.

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The IRS also imposes a 10% excise tax on any excess business holdings that are held by a private foundation. Excess business holdings are defined as any stock or interest in a business that is held by a private foundation and that exceeds 20% of the voting stock or total value of the business.

Private foundations are also subject to an excise tax on certain taxable expenditures. These include payments made to disqualified persons, expenditures made for political purposes, and any excess distributions made by the foundation. The rate of the excise tax on these expenditures varies and can be as high as 10%.