Question about Gigaset Dx800a

I don't think so. You can assume that the product would still cost 275.- with or without the voucher and that the "voucher" would be free. This was 25.- call credit at sipcall.ch for a new registration if you had previously bought a product here at Digitec. However, the info seems to be missing on the product page. It's quite possible that the offer is over and this hasn't been corrected yet. It is best to contact customer service for more detailed information.