My wife is a diplomat from Bolivia that works for an international organization. Her organization provides a home leave benefit for spouse and dependents every two years. This means that every other year we get a paid trip to Bolivia.

UN rules and her organization's rules clearly state that all home leave travel must be in economy class. What is unclear is whether its acceptable to upgrade the tickets using money, miles, or points.

She wants to clarify internally before we upgrade. If it were me I would just upgrade but she's more cautious about it.

Does anyone have any experience with this?