An additional real estate tax, known as the Supplemental Real Estate Tax may be issued to a taxpayer who has purchased a newly built home. If your real estate taxes are escrowed (paid on your behalf by your bank/mortgage company), you should make the mortgage aware that these are additional taxes to your original real estate bill. Supplemental Real Estate Taxes are subject to the same collection procedures as that of a real estate bill, including the placement of a tax lien on the property.