Received paiment

Hello there, @Evencio.

Thanks for taking the time to post your concern. I'm here to guide you in managing your transactions to make sure they will not be duplicated. 

When the customer makes a payment on the invoice, you'll need to record it in QuickBooks to link the payment transaction to the original invoice to stay balanced. 

Here's how to record invoice payments:

1. Open the customer invoice.
2. Select Receive payment.
3. From the Payment method dropdown, select the payment method.
4. From the Deposit to dropdown, select the bank account where you received the payment into. 
5. When you're done, select Save and close.

For more details about this process, check out this link: Record invoice payments in QuickBooks Online.

Once done, you can now match it to the downloaded payment from the Banking page. Matching transactions will create one record on your bank register.

Let me show you how to do it.

1. Go to the Banking menu, then locate the downloaded payment with the Match option in the Action column.
2. Select the downloaded transaction to expand the view.
3. Review the Matching records found in QuickBooks, then select the link next to each match to get more details.
4. Make sure this is the correct match. If this is the correct match, close the open transaction.
5. Click Match.

For future reference, visit this article to guide you more with matching your QuickBooks transactions with your real-life bank statements: Reconcile an account in QuickBooks Online 

Let me know in your reply if you have any additional concerns. I'll be around to help.