First establish exactly what needs permission
The statutory route is Section 73A. Before applying, identify the development already carried out and compare it with any existing permission, drawings and conditions. Do not assume the whole property is unauthorised where the issue concerns a particular change. [1]
Prepare an accurate record of the built situation and relevant dates. Distinguish retained work from any further alterations proposed as a remedy. The application should allow the council to understand what it is being asked to approve, rather than presenting an idealised drawing that no longer matches the site. [2]
The application still needs evidence
Use the appropriate application requirements, ownership information and supporting documents. Work being complete does not remove the need to explain its planning effects or satisfy relevant information requirements. Check the actual council checklist and the issues identified by the enforcement officer. [2][4]
Where a design change might make the development acceptable, agree how that change should be shown and described. Keep the submitted proposal distinct from any informal discussion about possible solutions.
The August 2026 policy on intentional development
Policy DM8 of the NPPF published on 17 August 2026 requires substantial weight to be given to an evidence-based conclusion that the unauthorised development was intentional when considering retrospective permission. The policy does not say every retrospective application must be refused. [5]
Be accurate about the sequence of events and any previous advice or permissions. The application should address the development's effects and policy position, not rely on the argument that undoing the work would be inconvenient.
Enforcement can affect the available route
Submitting a retrospective application does not automatically remove an enforcement notice or suspend its requirements. There are also restrictions linking retrospective applications and enforcement appeals: a council may decline a related application after an enforcement notice, and a previous related application can restrict a later ground (a) appeal. [3]
Get advice before choosing the route where a notice has been issued or is imminent. Keep all response and appeal dates separate from the application target date.
Check charges and separate approvals
Retrospective permission can affect Community Infrastructure Levy relief or exemption. The national guidance warns that previously expected relief may be lost, so check the financial consequences before selecting a remedial application route. [3]
Planning permission is also separate from building regulations approval. Regularising the planning position does not establish that completed work complies technically or provide a building control completion certificate. [6]
Once a decision is issued, read every condition and any required alterations. Retain the approval and evidence of compliance with the property's records; a retrospective grant is not a reason to overlook conditions attached to it. [2]