Forgot the thank you LieraMarie_A
I'm grateful for your swift reply and for providing us with supplementary details and screenshots, @g_Quik_Online. I'll guide you through the process on how to handle this situation.
Step 1: Undo the matched entry:
Since the transaction is matched to a downloaded entry, our first step is to unmatch it, allowing us to make the necessary changes.
- Go to Banking.
- Select tile for the bank or credit card account you downloaded the transaction from.
- Select the Categorized tab.
- Find the transaction you want to unmatch.
- Select Undo from the Action column.

- Click Continue.

Step 2: Delete the incorrect payment:
- Go to the Sales menu, then select Customers.
- Select the wrong customer (BAD).
- Look for the incorrect payment and click View/Edit.
- Click on More at the bottom, then choose Delete to remove the payment.

- Click Yes to confirm.

Step 3: Recreate the payment for the correct customer:
- Click +New and then Receive Payment.
- Select the correct customer (GOOD).
- Enter the payment date.
- Check the box next to the correct invoice.

- Click Save and close.
Step 4: Match the payments with the downloaded entry:
- Go to Banking.
- Select tile for the bank or credit card account you downloaded the transaction from.
- In the For Review tab, click the transaction to expand the view.
- Select the Find match option.
- Tick the payments you want to match.

- Click Save.
Step 5: Manually Reconcile the Transaction:
Since the incorrect payment was already reconciled, you'll need to manually reconcile the corrected transaction to ensure your accounts are accurate.
- Go to the Accounting menu and select Chart of Accounts.
- Find the bank account used for the deposit and click on View Register.
- Locate the new payment and mark it as "R" (for Reconciled) by clicking on the empty square twice in the "✔" column.

- Select Save and then Yes to confirm.
- Click Yes again to affirm.

Additionally, I've included a related article that might be of help in case you encounter any challenges during the reconciliation process: Resolve Reconciliation Issues.
If you come across any additional queries or complexities, please feel free to get in touch. Your success remains our foremost concern.