To apply for a security license, first call your state's department or office that deals with labor and business, such as Florida's Department of Agriculture or Washington state's Department of Licensing. Ask the office for any paperwork or procedures necessary to become licensed in your state or go to the office's website and attain the proper information.
Each state has basic requirements that need to be met to qualify for a license. One of these requirements is a minimum age of 18 or 21 years of age, with some states allowing an unarmed license for those who are younger than the minimum age. Background checks are usually required because of the nature of the job. If there is anything on your record that is questionable, you may have an opportunity to explain the issue. Be honest and describe the problem with as much detail as you can.
Many states provide the application online, but there are always paper applications for those who need them or who prefer not to submit personal information electronically. Some applications require some level of college education, experience in a similar type of job, transcripts of passed training courses or a potential job offer. All applications have a fee and many are only complete when turned in with additional material, such as proof of liability insurance. Once the application is submitted, await instructions for any additional steps issue by your state's office to become licensed, such as a qualification exam or training.