 Historically, many Canadian plates were replaced every year, although the most common practice in modern times is to send new validation stickers to vehicle owners every year or two, to indicate that the vehicle registration is still valid.Plates that are not up to date quickly attract the attention of law enforcement, because registration "renewal" is a transaction that can usually be undertaken only by the car's registered owner, once certain requirements have been met, and because registration fees are a source of government revenue.A delinquent registration sticker is often an indicator that the vehicle may be stolen, that the vehicle's owner has failed to comply with the applicable law regarding emission inspection or insurance, or that the vehicle's owner has unpaid traffic or parking tickets.