If your company is following GSA Per Diem rates they are correct travel is at 75%. I travel overseas on a govt. contract. To give you my last trip traveling to Jordan. I left on Wed. at 10: AM I charged 75% of Jordan Per Diem. My plane was canceled in VIE to Jordan and had to spend the night. Charged full VIE Per Diem for the day. Next day flew to AMN charged a full day Per Diem for AMN. Coming back we got on the plane at 0200 on Friday and arrived at the home at 1800 hrs. Per Diem was 75% of Jordan rate. Taxi tips come out of Per Diem. Taxi is a chargeable expense.