The Texas Comptroller has published guidance explaining that all agricultural and timber registration numbers expire on December 31, 2019. The publication also provides detailed information explaining how these exemptions apply. Registration numbers expire every four years regardless of when the number was first issued. The end of the current four-year session is December 31, 2019. Farmers, ranchers, and timber producers engaged in exempt activities will need to renew their registration by this date to continue making exempt purchases. Renewals can be completed online or over the phone. The Comptroller's office has mailed renewal information to affected taxpayers.