I've received a PCN/Notice but I wasn't the driver / I've bought or sold the vehicle and wasn't the owner at the time?
By law it's the person named on the notice who is liable to pay a PCN, not the driver. This will usually be the person to whom the vehicle is registered with the DVLA, however it may also be the buyer or seller of the vehicle, or a hirer/lessee, depending on the circumstances.
The driver can still submit representations however you would need to provide permission in writing for those representations to be formally considered.
If you receive a PCN for a vehicle you sold prior to the contravention date, or bought after it, please provide evidence of this eg a bill of sale or notification from your insurer of the date you stopped being insured on the vehicle.
Make sure to include the date and time of purchase or sale, as well as the name and address of the person/organisation you bought it from/sold it to.v