first off... is this a CANADIAN banknote? it certainly does not conform to any s/n convention used recently. any bank will be able to vouch for the authenticity of the note -- it is not illegal to possess a counterfeit note... just to knowingly try to pass it, so make certain you tell the bank your purpose.

if it does purport to be a Canadian banknote, there are certainly things to look for on the note -- check HERE for details.

if you have any more questions please ask and someone here can likely help!