All trees 10"+ in diameter are protected (5"+ for Texas persimmon, mountain laurel, Eve's necklace, silk tassel and bigtooth maple), except chinaberry, Chinese tallow, Japanese ligustrum, tree of heaven and Callery pear. Removing a protected, heritage (24"+ listed species) or ancestral (30"+) tree needs a permit.
How to apply: Submit a tree removal permit (one application per tree, with photos) to Public Works & Environmental Services, 512-891-9103. The City inspects and decides within 15 working days.
Texas law: cities cannot charge a tree mitigation fee for a tree under 10" at an existing one- or two-family home you live in (Local Gov't Code §212.905, HB 7, 2017). Since 2023, landowners can petition to leave a city's ETJ (SB 2038), so ETJ lines change; we read the live City of Austin jurisdiction map.
Official sources: sunsetvalley.gov/residents/city-regulations-and-permits/tree · codelibrary.amlegal.com/codes/sunsetvalley/latest/sunsetvall