HB 1766 mandates that appraisal districts rely on property appraisals submitted by property owners when determining real property values, provided specific criteria are met. The appraisal must be performed by a licensed or certified appraiser, comply with professional standards, and be conducted within a specific time frame. Property owners must notify the appraisal district of their intent to submit an appraisal and provide the appraisal by designated deadlines. The act takes effect on September 1, 2025, and applies to appraisals for tax years starting thereafter​.