I would like to ask for your assistance. I will appreciate any help with the below scenario: We invoiced about the customer for the parts on 10/07/2019. The customer picked up the equipment the same day and made a payment as well on 10/07/2019. The payment (check) has been deposited to the bank. Also, the payment has been recorded into the customer deposit account; therefore, the bank reconciliation went well. However, the payment has not been applied to the invoice. The month of October has been closed and all financial statements have been finalized.

We need to fix this without hurting the Account Receivables balance that has been reported on the balance sheet for the month of October. I would like to ask how to properly apply the payment to the invoice with no harm to the financial statement and reconciliation.

Thank you!