I Am Using The Correct VIN # But Your System Is Not Accepting

The car is a Kit car, MG TD. I am trying to sell and your system does not accept the VIN # because it is less numbers than standard VIN. Please advise David Pate 502-649-7659

When I Try To Impute The VIN Number It Says It Is Not Correct But I Know It...

I have verified the VIN number and have tried to add it to my information on your web site. It keeps rejecting it as not correct. Not sure what to do at this point.