If you do not renew your CNA certificate by midnight of the expiration date, your certificate becomes delinquent. A nurse aide with a delinquent certificate is not allowed to work as a CNA in Florida. Late renewal is possible but it requires additional fees. A CNA with a delinquent certificate has two years from the date the certificate expired to renew and pay the late fees; if late renewal does not take place, the certificate becomes null and void. In this case a nurse aide who wants to work as a CNA must retake the Florida certification exam.