Apply customer payments in Oracle, including ACH, checks, and electronic payments, ensuring accurate allocation to customer accounts and invoices. Research and resolve unapplied, unidentified, and incorrectly applied payments by reviewing customer account information and available payment documentation. Investigate payment discrepancies, including invalid PRO numbers, incorrect payment references, short payments, and other inconsistencies affecting payment application. Communicate with Collections teams to obtain customer information and resolve payment-related issues. Validated customer credits and processed write-offs in accordance with established procedures, obtaining management approval when required.