As part of recognition at my employer, you can get gifted dollars towards redeemable rewards. The only thing I'm really interested in is the prepaid Visa gift cards. I don't need overpriced stuff that I can get cheaper on Amazon/online or regular gift cards to stores that are 1:1 ratio.

I've never used one of these prepaid gift credit cards (Visa/MC/Amex) to purchase on United.com, do they work? What does one put in for billing address and phone, etc.?

Thanks!