There  are various reasons why the dollar amount listed on a voucher may not  match the sum total of all receipts attached to the voucher.  Please  note the following guidelines, and consult with the GSA or the College  Association if you have other questions:
      
If you are requesting partial reimbursement  for an expense, please write "Partial Payment" on the voucher (for  example, if have a receipt for $100 for refreshments but wish to be  reimbursed a lesser amount).
Taxes and tips will not be reimbursed.  If you mistakenly paid tax for a club expense or added a tip to a bill,
do not include these in the amount requested for reimbursement.  Include only the subtotal(s) indicated on the receipt(s), before tax and tip.