Thank you for the explanation but doesn't the credit card company charge a fee based upon the total charged amount?  So let's say my invoice is for $1000 and the credit card fee is 3%.  So the transaction fee is $30.  So I create a new service item called credit card fee and add it to the invoice.  Now the balance to be paid is $1030.  When I process the transaction, the credit card company will charge a 3% fee based upon the total which is now $1030.  So the new transaction fee is $0.90 more.  Not a big deal on a smaller invoice, but over time and on larger invoices it adds up.  So really I'll never fully collect the transaction fees from my customers for processing credit cards, right?