In NSW where the DMT issues the plates I discovered that I had been riding a motorcycle for one year that was unregistered and uninsured. The DMT (DVLA equivalent) had handed over the wrong plate, one number more or less, with the papers. When the person who had my plate returned to have the error corrected they gave him a new plate and simply cancelled my registration. Took an hour of "discussion" to get the problem rectified. I had never noticed the plate number was different to that on the documents.