To take advantage of the referral program, existing customers must fill out the referral form found below. In order to qualify a Softub Express purchase, both parties must be the original purchasers. The existing customer must provide Softub Express with the serial number of both softubs or the original invoice. Once the purchases have been confirmed, we will e-mail both parties their own unique coupon code, which can be entered at checkout when shopping online with Softub Express. The coupons cannot be combined with any other sales or offers.