I think they will only let you renew online now if I'm not mistaken. I tried to renew before mine expired and the site said I had to wait until it expired to renew. So after it expired I went back and tried to renew but then they told me since it was expired I'd have to get fingerprinted and get a new background check also. I wrote them and told them that they were the ones who told me to let it expire. So they wrote back and said since it wasn't expired very long they would go ahead and renew it. It took I'd guess 3 or 4 weeks til I got it in the mail. In other words it's a big fat cluster foxtrot over there and they make the rules up as they go along. If you turned in your request and haven't heard back in 2 months I'd write them. I got the impression they never get in a hurry unless you build a fire under them.
