Wirelessly posted (BlackBerry: BlackBerry8530/5.0.0.601 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)
I don't believe that use of a rate code is a "coupon" for purposes of credit-card coverage. And I suspect that an upgrade coupon would not void the coverage either. It's the free-day and dollars-off coupons that can cause mischief I think.