Yes. If it has a balance, it's activated. You don't even need a physical card - just the number on the card. We buy electronic Disney gift cards from the Target website to pay for everything Disney related and almost never buy those from the store.I checked the balance online and it is correct. But I can't find where you activate it on the Disney gift card website. Is it already activated once it's purchased from a store?
This is what we do as well. Just make sure to hang never get rid of the physical cards if you use them to book DCL or rooms. Disney will credit them if you have to cancel and refund you in currency for any amount over $1000.00.I got two physical Disney GCs as gifts and I’ve been keeping one on me and one in a safe place just in case it gets lost. I can buy more digital cards online at Target and transfer the balances between cards online. So far it’s worked really well and every bit of savings counts!