What is the deadline to file a protest?

A protest must be filed by May 15^th, or no later than 30 days after the Appraisal District delivers a Notice of Appraised Value to you, whichever is later.

However, if the protest deadline falls on a weekend or holiday, then the protest deadline is the first business day after that date.  If mailed, the protest must be postmarked by the deadline date.