When you find a movie, TV show, or music video you like in the iTunes Store, you can purchase and download it to iPhone. You can purchase movies and TV shows in standard (480p) or high definition (720p) format.
When you purchase a high-definition video on iPhone, a standard definition version compatible with iPod and iPhone immediately downloads for viewing. The high definition version appears in iTunes on your computer in the Downloads queue. You must be signed in to your iTunes Store account on your computer to view and download items from the Downloads queue.
Rented movies are available in standard definition only (not available in all regions). See Watching Rented Movies.
Tap Preview.
Tap Buy or Rent.
Sign in to your account as requested, then tap OK.
If you don’t have an iTunes Store account, tap Create New Account to set one up.
Your purchase is charged to your iTunes Store account. For additional purchases made within the next fifteen minutes, you don’t have to enter your password again.
Once you purchase an item it begins downloading and appears in the Downloads screen. Rented movies won’t begin playing until the download completes. See Checking Download Status.
Purchased videos are added to a Purchased playlist on iPhone. If you delete the Purchased playlist, iTunes creates a new one the next time you buy an item from the iTunes Store.
You can redeem iTunes Store gift cards, gift certificates, or other promotional codes to make purchases. When you’re signed in to your account, your remaining store credit appears with your account information at the bottom of most iTunes Store screens.
Tap Music, then tap Redeem at the bottom of the screen and follow the onscreen instructions.