When the property is appraised during the lending process, the homeowner will be advised of their supplemental assessment amount. The owner will be given an opportunity to discuss the valuation, apply for a Homeowner’s Exemption and file an Assessment Appeal if needed. The County will then calculate the supplemental tax and a bill will be mailed to the homeowner. This can take between 3 weeks to 6 months after close of escrow. A lien is put on the property for the supplemental taxes, so the homeowner must be careful to pay the taxes by the date noted on the supplemental tax bill.