Bailiffs turned up out of the blue about a mystery PCN

Any of the following could apply

You bought a second-hand vehicle and the bailiff is recovering an unpaid PCN by the previous keeper. Make a third party claim to comtrolled goods

The address on the V5 is wrong and the bailiff has traced you. Appeal the PCN on the grounds you were not given a Notice to Owner (NTO)

You recently moved or changed address after the date of the traffic offence. Appeal the PCN on the grounds you were not given a Notice to Owner (NTO)

An ANPR Van found your vehicle parked on the street.