Q: Why can't I redeem my iTunes gift card??

Restart your iPad and try again.

Sign out of your Apple ID in the iTunes Store app and sign in again.

If those don't work, contact iTunes Support

https://www.apple.com/support/itunes/contact/

I'm also having the same problem on my PC. I'm going to give it a half hour and try again.

You can always check the status of Apple Services. Looks like everything should be fine (I also checked before replying to the original post).

If there is an Apple-wide issue, it should show up here.

https://www.apple.com/support/systemstatus/

Did any of my steps help or was it just an temporary iTunes Store issue?

Maybe they had a little bit of a down time. Glad it worked for you!

I'm having the same issue.  Tried iPhone, iPad, Mac Mini.  No Luck

Any tips on how you resolved the issue??

In your case, I would try signing out of your Apple ID and then signing back in and trying again.

If you are having this issue on multiple devices it is either related to the iTunes Store being down, or an issue with your Apple ID. It doesn't look like the iTunes Store is don but it could be a minor outage such as what QueenCandy experienced.

Try the steps in the article below. If they don't work, contact iTunes Support

If you can't redeem your iTunes Store Gift Card or code - Apple Support

I am having the same problem on my iphone, ipad, and imac when I try to download an app. I tried logging out/in. No resolution.

TEMPORARILY UNAVAILABLE

This feature is temporarily unavailable. Try again later.

I checked the apple site for issues and they report that there are no issues.

If only Apple could courteously post  a notice to let its customers know of any outages rather than say there are no issues. That would be awesome. Hours of dread and frustration could be reduced.

Apple is very secretive about everything they do, and rightfully so. If they told people they were working on the iTunes Store, everyone would jump to the conclusion that something new and innovative is coming out!

I would just try again later and if you still have problems, contact iTunes Support to rule out any Apple ID issues.