Footway (pavement) parking
Where parking restrictions are marked on the road, for example yellow lines, those restrictions also apply to the footway (pavement). Therefore parking tickets (PCNs) can be issued to vehicles which are parked in contravention of the restrictions.
http://www.nidirect.gov.uk/parking-enforcement
Footway (pavement) parking is not permitted at any time along the length of urban clearways and parking tickets (PCNs) can be issued to vehicles parked in contravention.
Apart from urban clearways, there is no general ban on footway (pavement) parking. Where there are no parking restrictions marked on the road, parking tickets (PCNs) cannot be issued to vehicles on the footway (pavement). If, however, a problem of obstruction arises as a result of vehicles parked on a footway, that situation is a matter for, and can be dealt with by, the PSNI.