I want to re-register the license & insurance on my motorcycle.

The license & insurance is not due to expire until Sept 15, 2012

How far in advance of the expiration date can a vehicle registration be renewed?

Thanks for any assistance.

Does not really matter, the renewal starts on the expire date of the old one anyway.

If you late you have to pay partly tax for the overdue time and it starts the day you got there

Same for the insurance. (Exept that they wont cover the overdue time)

Your bike is already registered (if you already have the green registration book) so you do not need to do anything.

However if you mean you wish to Tax the bike then you will need the book and the CTPL policy certificate to show at the DL Office. As to timing, this can be done near the expiry date, however give your Broker a week or so to get the best prices for the voluntary insurance.

you can buy the basic insurance at the office, its a least a month before maybe longer.