Deductions & credits

You mention "EMPLOYER" so if you are a waged employee that gets a W-2 at the end of the year  then you cannot deduct any expenses.

 

However if you are self employed then ALL of the income including the per diem is reported as such and then you can deduct the full GSA rate and the allowed percentage will be calculated by the program ... enter them carefully in the correct places in the travel and meal expenses section.