Footways(pavements) are not footpaths:
The legal status of footways and footpaths differs: a footway runs alongside carriageway(i.e. a road), whereas a footpath is located away from it(e.g. between buildings or through open countryside). Cycling on a footpath normally constitutes only a trespass against the landowner.
This is a civil and not a criminal matter, i.e. neither the police nor a PCSO can take enforcement action. Instead, an aggrieved landowner can either ask someone cycling on a footpath over their land to leave, or they can seek a court injunction and/or damages against them.
By-laws and Traffic Regulation Orders2(TROs):
The exception to the above is where the relevant authority has passed a by-law or TRO, made under the Road Traffic Regulation Act 1984, prohibiting or restricting cycling on a particular footpath. By-laws and TROs have the force of law and non-observance may be penalised by a fine.