5 CFR § 3101.106 - Additional rules for Internal Revenue Service and Treasury Inspector General for Tax Administration employees.
The following rules apply to the employees of the Internal Revenue Service and the Treasury Inspector General for Tax Administration and are in addition to §§ 3101.101 through 3101.104.
(a) Prohibited recommendations. Employees of the IRS or TIGTA shall not recommend, refer or suggest, specifically or by implication, any attorney, accountant, or firm of attorneys or accountants to any person in connection with any official business which involves or may involve the IRS.
(b) Prohibited outside employment. Involvement by an employee of the IRS or TIGTA in the following types of outside employment or business activities is prohibited and shall constitute a conflict with the employee's official duties pursuant to 5 CFR 2635.802:
(1) Performance of legal services involving Federal, State or local tax matters;
(2) Appearing on behalf of any taxpayer as a representative before any Federal, State, or local government agency, in an action involving a tax matter except on written authorization of the Commissioner of Internal Revenue or the Treasury Inspector General for Tax Administration;
(3) Engaging in accounting, or the use, analysis, and interpretation of financial records when such activity involves tax matters;
(4) Engaging in bookkeeping, the recording of transactions, or the record-making phase of accounting, when such activity is directly related to a tax determination; and
(5) Engaging in the preparation of tax returns for compensation, gift, or favor.
(c) Seasonal employees. Seasonal employees of the IRS while in non-duty status may engage in outside employment or activities other than those prohibited by paragraph (b) of this section without obtaining prior written permission.