changing phone and want to cancel prepaid

Hello @khoale, we're happy to provide the steps to cancel your Prepaid Plan. 

If you don’t make any payments, your AT&T PREPAID service shuts off 60 days after your balance runs out. Don’t want your service anymore? Be sure to: 

Cancel AutoPay for your AT&T PREPAID account you need to be logged in. Your initial password is the last four digits of your wireless number.

1. At the top of the page, select Home.
2. Select Manage AutoPay.
3. Select End AutoPay.
4. Follow the prompts to confirm cancellation of your AutoPay.

Let us know if you have any questions. Thanks for reaching out to us on Forums.

Alasani, AT&T Community Specialist 

Canceling prepaid as a simple as turning off the auto pay switch in your online account and stopping refills.

If you intend to keep your phone number, porting your phone number to a new provider also cancel service