When is the deadline to apply?

It is a reduction in the taxable value of your primary residence, applied before tax rates are calculated. It also unlocks the cap on yearly increases in taxable value. You have to apply for it; it is not automatic.

File an application with the appraisal district for your property's county: Comal Appraisal District or Guadalupe Appraisal District. The form is free, and you typically apply once as long as you stay in the home.

For a homestead, the taxable appraised value generally cannot rise more than 10% above the prior year's appraised value, even if the market value rises faster. It applies to the taxable value, not to the tax rate or the amount of your bill.

No. The seller's exemption generally ends when the property is sold, and the new owner has to apply for their own once the home is their principal residence.