I'm here to ensure the credit card is attached to the right customer, stephanie.

Currently, it's not possible to delete your customer's credit card information. However, we can edit and replace it with a non-transacting number, which will overwrite the saved credit card info from customer 2. Here's how:

1. Go to Customers & leads, then choose Customers.
2. Select the customer name and hit Edit.
3. Go to the Payments section. Then, select the credit card number under the Preferred payment method field.
4. Click Add on the Credit Card information window.
5. Change the Credit card number to a non-transacting test card number like 4111-1111-1111-1111.
6. In the Expiration date, choose any date in the future and tap Save.

After doing so, you can now add the credit card to the appropriate customer.

Moreover, here's a helpful resource to guide you in recording partial payment for an invoice or recording payment for a single invoice: Record invoice payments in QuickBooks Online.

Come back and send a reply below if you have other concerns about managing your customer's credit card information. Take care!