Which document is invalidated if the owner of the delinquent property pays the required delinquent tax?

When the owner of a delinquent property pays the required delinquent tax, the document that is invalidated is the Certificate of Redemption. This certificate represents the process through which a property owner can reclaim their property after it has been sold or the tax lien has been executed due to unpaid taxes. Once the delinquent taxes are paid, the certificate becomes unnecessary because the property is no longer in a status where it is subject to redemption.

In contrast, the Certificate of Sale is a document that shows the sale of the property due to tax delinquency and does not become invalid with the payment of taxes; it remains as a record of the transaction. The Notice of Levy and the Real Property Tax Receipt also serve different functions: the Notice of Levy indicates a claim against the property for unpaid taxes, while the Receipt confirms payment and does not become invalidated by payment. Therefore, the correct answer highlights the specific transactional nature of the Certificate of Redemption in relation to the payment of delinquent taxes.