If the enforcement notice is not complied with by the end of the period for compliance an offence is committed and the planning authority can prosecute whoever is responsible for this non-compliance. If the occupier continues to breach an enforcement notice after prosecution they can be prosecuted for further breaches and the fine is set at a daily rate for the period the breach continues for. Also, planning authorities can take what is called “direct action” to remove the development, e.g. demolish an unauthorised building, although normally such action is taken for the more major planning breaches.
Under the Proceeds of Crime Act 2002, a developer can have profits from an unauthorised development confiscated once the enforcement notice is effective, e.g. if a landlord has converted a house into a number of flats and there is an effective enforcement notice against this, the profits from the rental income can be taken away from them. An enforcement notice once served becomes a Land Charge so subsequent purchasers of the property should be aware of it and would be guilty of an offence for not complying with it, i.e. it is effective permanently.