Allowing your teaching license or certification to expire means you can no longer legally teach in a public school in the United States. Renewing your certification could be a simple matter of filling out some forms, or it could involve a host of requirements. For example, you may have to take new college-level courses and pass new certification exams.

Reapply for Certification

If your teaching certification expires, you must apply for recertification through your state's department of education. The requirements vary by state and often depend on how long you've been away from teaching. A school district offering you employment may be able to submit certification materials to the department of education for you. The requirements typically include certified copies of your college transcripts and proof of experience. If no school district is hiring you, you must gather these materials on your own and submit them to the appropriate licensing division.

Competency and Knowledge Tests

Depending on state law and how long you've been away from teaching, you may need to retake competency and knowledge tests required for your subject and grade level. You can usually obtain study guides and practice tests from your state's department of education to prepare for the exams. If you're an out-of-state teacher, the exam scores from another state may be satisfactory to renew your teacher certification if the two states have a reciprocity agreement.

Background Checks

The law requires you to submit to new background checks administered by state law enforcement and by the FBI to renew certification of an expired teacher's license in any state. Your employing school district may submit your identifying information, including your Social Security and driver's license numbers, to these agencies on your behalf. Or you may submit the materials on your own if you currently have no teaching contract. Almost any criminal background will exclude you from renewing your teaching credentials.

Continuing Education Credits

Many states require continuing education to preserve or renew teaching certification. Some states, like Pennsylvania, require teachers to attain master's degrees in their fields within the first six years of teaching to preserve their certification. Other states, like Washington, require at least 150 credit hours of continuing education during the previous five years to reinstate an expired teaching license. Check with your state's department of education to determine which continuing education rules apply in your case.