Once you successfully completed the first 2 steps above, you will need to file for the required Texas LTC application with the Texas Department of Public Safety. Applicants must be at least 21 years of age (unless you are active duty military) and must meet the Federal qualifications in order to purchase a handgun. You may however take the proficiency class portion at age 20, but since you must attest to being 21 on your application, the application may not be submitted prior to your 21st birthday in order to comply with legislation.