Gift cards applied to account balance

You are referring to using the Apple Store? From what I can tell, if you actually redeem a gift card (and it has to be the right kind) the balance gets added to your Apple ID. Depending upon where you live you may be able to buy different things with Apple ID balance, but there are also restrictions. I don't think there are limits to the number of cards you can redeem but then there may be problems with using this for some purchases. Otherwise Apple Store gift cards are like cash, but then you run up against the 8 card limit.

This article explains the different kinds of cards Apple uses and has links on how to redeem them and what can be purchased with each kind. Click on the link --> What type of gift card do I have? - https://support.apple.com/HT204199

Payment, Financing, Refunds and VAT - Shopping Help - Apple

"You can use up to eight Apple Gift Cards at a time when you purchase online from Apple, or if you’re placing an order by calling 1‑800‑MY‑APPLE. You can use your gift card(s) with one credit card and your Apple Account Balance to pay for your purchase."

All I know is what I read in the documentation (this forum is for users to help users). It depends upon the card, about which I earlier provided a link. Apple has a bewildering variety. If it is one which you can redeem vs. just use as cash directly, and you choose to redeem it, it gets applied to your Apple ID balance. What you can buy with Apple ID balance depends upon the country where you live (don't forget I have no idea if you are sitting in a yurt in Mongolia).

To learn 'What you can buy with your Apple ID balance'click here --> https://support.apple.com/HT211187

If it is an Apple Store card then it is basically like cash. You don't redeem it as such, you just turn up with 8 or fewer, put them down on the counter and say you want an iMac or whatever. If you're in the US and you can use your Apple ID balance for what it is you want to buy, you don't need the cards anymore once you have redeemed them to your account. Your Apple ID has the credit attached to it and it isn't seen as individual cards, just a $ amount. This is probably more the Target model. Balance can be added to an Apple ID by other methods too but in the end it is just seen as so many $ credit in your Apple ID.

If you have a specific purchase in mind and want to make sure you have the right kind of cards and what to do with them, ask Apple:

Contact Apple for support and service --> "See a list of Apple phone numbers around the world."

Click here --> https://support.apple.com/HT201232