We've not transitioned . . . we've always used actuals. The company that just purchased us, however, uses a per diem. So we will actually be going the other way . . . transitioning from actuals to allowance.
I'd be interested in seeing some of the responses you get, @RichardG!
We have both actuals and per diems currently in place. I would suggest you have some clear guidance on actuals. Currently, our policy indicates meals will be reimbursed at actual/reasonable costs. This is open to interpretation. What I consider reasonable may differ from what you consider reasonable. I may choose to eat breakfast at one location and consider it 'reasonable' to also purchase my favorite Starbucks drink and a muffin as part of my breakfast. Often times, leaders are calling my department to obtain guidance on what is considered 'reasonable'. We end up pointing them to the per diem for the location as guidance. In my opinion, per diem offers the guidance and limits which actuals do not.
Absolutely agree with you. We've found some very interesting purchases when the itemized receipts are attached! Actually, we do not reimburse lunch (unless required by statutory requirements). The time of purchase on the receipts have become key to us as well when reviewing meal expenses.
Speaking of alcohol.... If expensing one meal (i.e. eating alone), it is reasonable to purchase one alcoholic beverage. When expensing meals with additional guests our rule of thumb - alcohol cannot exceed 30% of the total meal value. Anything over and above may be considered excessive. Of course, business purpose and other expenses submitted on the same day are taken into consideration. It's been quite helpful for us to have this guidance in place.