Your Apple Developer Account expires annually, 1 year from the date that you first purchased or last renewed it. The cost is $99/year. Apple sends reminder notifications as does Smarter Agent, but if the account expires before you renew it your iPhone & iPad apps will be removed from the stores until you renew the account.
Here’s how to renew your account, regardless of if the account has expired yet or not.
- Go to https://developer.apple.com/programs/ and Click “Account” to log in. If you are unsure of your UN and PW, contact your account manager.
- Click "RenewMembership" next to the iOS Developer Program Membership alert at the top.
- Click “Continue.”
- On the “Review your purchase details” page, click “Continue.”
- Check the “Automatic Renewal” checkbox.
- Click “Buy Now.”
- Log in again.
- You’ll then be promoted to fill in your credit card information to pay for an additional year of service with Apple.
Apple provides further assistance via their FAQ here: https://developer.apple.com/support/ios/program-renewals.php.
If your apps did get removed from the store, once you renew the account they should be available again for download within a few hours.
Please let me know if you have any questions.