You may accept payment from a non-Federal source or authorize an employee and/or the employee's spouse to accept payment on your behalf only when-
(a)
You have issued the employee (and/or the employee's spouse, when applicable) a travel authorization before the travel begins;
(b)
You have determined that the travel is in the interest of the Government;
(c)
The travel relates to the employee's official duties; and
(d)
The non-Federal source is not disqualified due to a conflict of interest under § 304-5.3.