Why did my Sullivan's Island property tax bill go up even though I did not renovate?

A Sullivan's Island property tax bill can rise without any renovation because the underlying assessed value or the millage rate can both change independently of anything the owner did to the home. Charleston County periodically reassesses property values based on market activity, and a strong sales market on the island can push assessed values up even on an untouched home. The millage rate itself is also reset annually by the county, town and school district, and any of those increases will raise the bill on its own. Brian Beatty can help a Sullivan's Island owner check whether the increase came from a reassessment, a rate change, or both.