A) Go down to a local Best Buy store, and they should be able to put those together into one gift cards, or larger amounts onto few gift cards, so you can use them all online. B) Try using them towards larger valued E-Gift cards online at bestbuy.com in order to have fewer than 10, and send them to yourself. Can I stack best buy gift cards online? Answer Save. 1 Answer. Relevance. Government Benefits Expert. Lv 4. 1 decade ago. Favorite Answer. You should be able to. Once you use the first one, the system should prompt you for an additional form of payment, and you can use the second one at that time. 0 0 0. Online or in store, a Best Buy Gift Card gives you the power to choose what you want, when you want it. And, our Blue Shirts and Geek Squad Agents are ready to answer whatever questions you have. We’ll listen, not lecture. No returns and no refunds on gift cards. This item is not eligible for return.