Retrospective planning permission is the granting of planning approval after construction works or changes of use have been undertaken, whether they have commenced or completed.
There are many reasons why there is a need for retrospective planning application, including for work that was considered to be permitted development which later transpires, for whatever reason, not to be the case.
Local Authorities may also invite owners to submit an application in advance of formal enforcement action being taken where it is suggested planning permission is required.