Well there is no limitation on the mail-in form. In my case i'll mail the refund request with one invoice (with 3 purchases on it) and 3 forms all in the same envelop... The only limitation i can see on the form is that we need to supply 3 forms for 3 refund requests... The only thing i'm curious to see is that the product is taxable here... and there is no mention anywhere on the form they will reimburse the taxes neither the stamp... so it might actually cost me a bit to try the product but hey... it's cheaper anyway than paying full price!