If you notice the mistake before 8:30 pm ET on the same day you paid the bill, you can cancel the payment:

1. From the app's home screen, select Move money
2. Select Pay bills
3. Select Manage bills
4. Go to Pending Payments and select the bill payment you want to cancel
5. Select Cancel payment

You can then set up a new bill payment for the correct amount.

If you don't notice the mistake until after 8:30 pm ET, please contact the merchant you're paying for support.