Allowable, subject to these restrictions:
Use the lowest available coach fare. You must use U.S. carriers for federally funded travel unless the Grants Accounting Office approves an alternative. If it's a "code share" flight (shared by several airlines), the ticket bought with federal funds must be purchased from the U.S. carrier.
Many funding agencies require prior approval for foreign travel or do not allow it at all. Yes, Banner has only one account code for travel, but if the awarded budget does not specify foreign travel, check with the Grants Accounting Office to be sure it's allowable.
You must use U.S. carriers for federally funded travel unless the travel meets certain criteria (check the agency guidelines to be sure!) and the Grants Accounting Office office approves the alternative.
You should register in Middlebury's Travel Registration Program for any travel abroad: http://www.middlebury.edu/international/travel
Meals and Lodging
Follow College policies for reimbursement for business travel. Faculty may follow the same policies as for the FPDF (Faculty Professional Development Fund) when budgeting and charging grant-funded expenses for lodging and meals. You may use federal per diem rates for simplicity (but if you do so you must also follow the federal policies for partial days or single meals on days when some meals are covered by conference fees). You may submit receipts that total more than the per diem rate if you document and can justify your expenses.
Use the current College reimbursement rate, provided in the Budget Office FAQs.