Quick answer
Estimate taxes using the expected assessed value after transfer, local millage and non-ad valorem assessments—not only the seller’s current payment. County property-appraiser estimators can help, but the official future bill is not known at offer time.
If taxes are escrowed, the estimate affects the total monthly mortgage payment and initial escrow funding.
Why the seller’s bill can be lower
A long-time owner may have homestead exemption and accumulated Save Our Homes assessment protection. Florida’s Department of Revenue warns that a buyer’s taxes may be higher after ownership changes and the property is reassessed.
Exemptions do not automatically transfer with the sale. The buyer applies based on eligibility and deadlines.
Homestead and portability
An eligible owner who makes the home a permanent residence may apply for homestead exemption. A qualifying Florida homeowner moving from a prior homestead may also be able to transfer part of the Save Our Homes assessment difference.
Portability is not the transfer of the old exemption itself, and qualification is determined by the county property appraiser. This is general mortgage education, not tax or legal advice.
Build the estimate into the offer
Use the county’s current records, tax estimator and known district or non-ad valorem assessments. For new construction, confirm whether the current bill reflects vacant land rather than the completed home.
Refresh the mortgage payment estimate when assessed-value, exemption or special-assessment assumptions change.