how do unauthorize my credit card so my kids can't charge to my itunes account?

Hey msumer,

Thanks for the question. The best step to take is to change your Apple ID password so you are the only person with access. However, you may want to look into setting up individual accounts for your children, then use iTunes Store Allowances:

It sounds like iTunes Store Allowance is exactly what you are looking for:

iTunes Store Allowance

http://support.apple.com/kb/HT2105

With iTunes Allowance, you can send a monthly iTunes Store credit to anyone with an iTunes Store account. It's a great way for parents to manage their children's spending on the iTunes Store, App Store, and iBooks Store.

Good to know

- Every month, the allowance amount you've set will automatically be added to your recipient's iTunes Store account.

- The amount can be anything from 10 to 50 USD.

- You'll be charged the full allowance amount on the first of each month (it'll be the same amount every month).

- You can reassure your lucky friend or family member that they don't need to spend all of the allowance each month; any remaining amount carries over to the next month.

What you'll need

- The latest version of iTunes for your Mac or PC.

- An iTunes Store Apple ID with a credit card on file.

- An iTunes Store Apple ID for the recipient (it's usually their email address).

Thanks,

Matt M.