The Fujitsu rebate form specifically states a COPY of the receipt is what is required. This is repeated in the fine print.
So I guess you'll only get rejected if you send them the original. (grin!)
However, be sure you get a receipt from your dealer that shows all the required info. Fujitsu requires that the receipt show the name and "full" address of the authorized dealer, your name, the qualifying plasma you purchased, the date of purchase, and the price paid. The receipt need not show the serial # of your plasma although you do have to include that on the rebate form itself.
Only a copy of the "receipt" will do. Packaging slips, credit card statements, and shipping documents are explicitly excluded.
Oh and you are limited to no more than 5 rebates per address, so if you need a 6th plasma for the assistant gardener's cottage, you'd best arrange for it to be purchased by a friend.