Section 173A: changing, relaxing or withdrawing an enforcement notice

 

A Section 173A enforcement notice request is one of the routes that can still be useful after an enforcement notice has taken effect, and even after an enforcement appeal has finished. It does not reopen the appeal. Instead, it asks the local planning authority that issued the notice to use its statutory discretion to withdraw the notice, waive or relax one or more of its requirements, or extend the time allowed for compliance.

This can matter enormously where the planning problem has moved on. A later owner may be willing to stop the unlawful use, a different lawful arrangement may now deal with the planning harm, or a particular physical reinstatement step may no longer serve a useful purpose. Section 173A gives the council room to respond to that without pretending the original notice never existed.

There is one warning to keep firmly in mind. Stopping the original breach does not necessarily mean that every requirement of the enforcement notice has been complied with. A notice may require both the use to stop and physical works to be carried out. Unless those remaining requirements are formally relaxed, waived, withdrawn or displaced by a later planning permission, they can continue to matter. See also our guides to enforcement notices and appeals, non-compliance with an enforcement notice and buying property with an enforcement problem.

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What a Section 173A enforcement notice request can change

 

Section 173A of the Town and Country Planning Act 1990 gives the local planning authority three particularly useful choices. It may:

• withdraw an enforcement notice that it issued
• waive or relax any requirement of the notice
• extend a period specified for compliance

The Act expressly says these powers can be used whether or not the notice has already taken effect. That is why section 173A can still be relevant where the original appeal deadline has gone, or an appeal has already been dismissed and the notice is in force.

If the council exercises the power, section 173A(3) requires it immediately to notify everyone who was served with the notice, or who would have to be served if the notice were reissued. Withdrawal is not the same as permanent immunity: section 173A(4) says withdrawing one notice does not prevent the authority issuing another notice if it still has the power to do so.

There is another important limit. Section 173A lets the authority relax a notice. It is not a power to make the requirements more onerous. In Pathfield Estates Ltd v London Borough of Haringey [2023] EWHC 1790 (Admin), the Divisional Court treated that distinction as important. A council may decide that a less demanding outcome is acceptable, but it cannot use section 173A as a free-standing power to replace the notice with a new and more burdensome requirement.

 

Ground (f) on appeal or section 173A later?

 

They can look similar from a distance, but they do different jobs.

Ground (f) is an appeal ground under section 174. It argues that the steps required by the notice, or the activities it requires to cease, go further than is necessary to remedy the breach or the injury to amenity caused by it. The appeal must be made before the enforcement notice takes effect. The Planning Inspector then decides whether the requirements should be cut back. Our enforcement appeal grounds page explains that route in detail.

Section 173A is different. It is a discretionary power held by the local planning authority. It can be used before or after the notice takes effect, including after an appeal has ended, but the owner cannot demand a fresh merits decision simply because a different solution now looks sensible. Asking under section 173A does not revive an expired appeal right and does not automatically suspend the notice while the council considers the request.

The same distinction applies to time. Ground (g) is the appeal ground used to argue that the original compliance period is too short. Section 173A gives the council a separate power to extend the compliance period later.

 

Negotiating a different route to compliance

 

Section 173A is often most useful where everybody agrees that the unlawful position should end, but there is a sensible argument about exactly how the land should be left afterwards.

Take a house which an enforcement notice says has been unlawfully converted into several self-contained units. The notice requires the unlawful use to cease and also requires the building to be restored completely to its former layout. Years later, a new owner wants to end the unlawful use but proposes a different lawful residential configuration. That may remove the planning harm while making some of the old physical reinstatement requirements unnecessary.

The owner can ask the authority to waive or relax those particular requirements under section 173A. What the owner should not do is assume that changing the use alone amounts to full compliance. If the notice still contains a separate requirement to remove kitchens, reinstate walls or restore a particular layout, that requirement remains important unless it has been properly dealt with.

A negotiated alternative also needs to be lawful in its own right. Section 173A does not itself grant planning permission. If the new configuration needs permission, a retrospective planning application, a fresh planning application or, where appropriate, a certificate of lawfulness may still be required.

 

Partial relaxation and extending the compliance period

 

The authority does not have to choose between leaving the notice untouched and withdrawing it completely. Section 173A allows a requirement to be waived or relaxed in part. That can be a much better fit where most of the notice remains necessary but one item has become unnecessary, impractical or disproportionate in light of a lawful alternative.

The authority can also extend the compliance period. A request for more time is much stronger when it explains what still has to happen and gives a credible programme rather than simply asking for delay. Evidence might include contractor availability, tenancy arrangements, relocation steps, building-control sequencing, finance, a timetable for an associated planning application or other matters that genuinely affect how quickly compliance can be achieved.

The power exists even after the original period has expired, but that should never be treated as a reason to wait. A request under section 173A does not stop the compliance clock by itself, and it does not automatically prevent prosecution or direct action by the council.

 

Get any relaxation or waiver clearly confirmed in writing

 

This is where Pathfield Estates Ltd v London Borough of Haringey [2023] EWHC 1790 (Admin) becomes particularly useful. The enforcement notice required a property which had been used as five flats to be restored to two flats. The five-flat use stopped. Officers accepted conversion to a single dwelling as satisfactory for compliance and sent closure letters saying the notice had been complied with to the council’s satisfaction. Years later the property was being used as six flats and a prosecution followed.

The Divisional Court upheld the conclusion that the requirement to restore the property to two flats had not been waived or relaxed under section 173A. The court stressed that a planning authority can say what it is prepared to accept as satisfactory compliance without necessarily waiving the strict requirement in the notice. The absence of the statutory notification under section 173A(3) was not conclusive by itself, but it was important evidence that no formal variation had been made.

That is a powerful practical lesson. If the agreed solution depends on a requirement being removed or relaxed, ask the authority to confirm the section 173A decision expressly. The confirmation should identify the enforcement notice, the exact requirement affected, the extent of the waiver or relaxation, any revised compliance period and the date from which the decision applies.

A letter which merely says the council is satisfied for the moment, is closing its file, or does not intend to take action is not necessarily the same thing. Under section 181, compliance does not discharge an enforcement notice, and a requirement to discontinue a use normally continues to bite against a later resumption of that use.

 

What about historic non-compliance and criminal liability?

 

This needs care. Once the compliance period has expired, a continuing failure to comply with an enforcement notice can amount to an offence under section 179. A later section 173A agreement should not be assumed to erase criminal liability that may already have arisen.

Section 173A itself does not contain the express saving for past offences that appears in section 180(3), discussed below. Equally, the legal effect of a waiver, its timing and any prosecution already in view can be fact-sensitive. If the compliance period has already expired, the section 173A request should therefore be handled alongside advice on prosecution risk rather than as though it rewrites history.

There is a separate provision worth knowing about. Section 172A allows an authority, in the circumstances set out there, to give a person who has been served with an enforcement notice a written assurance about the risk of prosecution under section 179. That is legally different from relaxing the requirements under section 173A. Where criminal exposure matters, a planning enforcement solicitor should consider the two provisions together.

 

When the property has changed hands

 

An enforcement notice is not wiped away by a sale. The practical burden can pass to a purchaser who had nothing to do with the original breach, and buying innocently does not create a fresh right of appeal against a notice whose effective date has already passed.

That can make section 173A especially useful for a new owner who is genuinely trying to resolve an inherited problem. The authority is still exercising a discretion, so the ownership change is not a trump card. But evidence that the new owner did not cause the breach, has investigated the notice promptly, has stopped or is stopping the unlawful activity and has put forward a credible lawful solution can all help demonstrate why a proportionate relaxation or extension deserves proper consideration.

Our guide to buying a house with an enforcement problem deals separately with searches, the enforcement register, section 179 defences, indemnity insurance and possible claims arising from the purchase.

 

What evidence can make a section 173A request stronger?

 

A good request makes it easy for the enforcement officer to see exactly what is being asked for and why the planning purpose of the notice will still be achieved. Depending on the case, useful material can include:

• a copy of the enforcement notice and any appeal decision, with the precise requirements highlighted
• a short chronology explaining what has happened since the notice took effect
• plans, photographs or a schedule showing the current position and the proposed lawful end state
• a requirement-by-requirement explanation of what will be complied with, what should be relaxed and why
• evidence that the harm identified in the notice or appeal decision will be removed
• a realistic programme for any remaining works and a reasoned request for any extra time
• details of any planning application, certificate or other consent needed for the alternative solution
• relevant ownership history where the present owner inherited rather than caused the breach
• draft wording for the relaxation or extension so there is no ambiguity about the outcome sought

There is no prescribed planning application fee simply for asking the authority to exercise section 173A. Professional fees and the fee for any separate planning application or certificate are different matters. See our guide to planning application fees for those statutory charges.

 

Section 180: what happens if planning permission is granted later?

 

Section 180 of the Town and Country Planning Act 1990 deals with a different situation. Where, after an enforcement notice has been served, planning permission is granted for development which was carried out before that permission was granted, the notice ceases to have effect so far as it is inconsistent with the permission.

This is an automatic statutory consequence of the later permission. It does not mean the whole enforcement notice disappears. If the new permission authorises only part of what the notice was aimed at, the inconsistent part of the notice falls away but the remaining compatible requirements can continue to bite.

For example, if a notice requires an unauthorised building to be demolished and a later retrospective permission lawfully authorises retention of most of that building, the demolition requirement cannot continue to operate against the part now permitted. But if an additional floor, use or other element remains outside the permission, section 180 does not give it a free pass.

The wording is also important because section 180(1) is concerned with permission for development carried out before the grant of that permission. Do not assume that a permission for a wholly future alternative scheme automatically neutralises an existing notice merely because the two would eventually be inconsistent.

Most importantly, section 180(3) expressly says that a notice wholly or partly ceasing to have effect under section 180 does not affect liability for an offence arising from an earlier failure to comply. Later permission can change the future effect of the notice. It does not retrospectively wipe out an offence already committed.

 

Section 173A and section 180 are not the same thing

 

The distinction is useful:

• section 173A depends on the local planning authority deciding to withdraw, waive, relax or extend the notice
• section 180 operates because a later planning permission is legally inconsistent with all or part of the notice
• section 173A can be used even where no new planning permission has been granted
• section 180 does not wipe out liability for a previous offence

In a complicated case the two can sit alongside one another. A later permission may remove some requirements automatically under section 180, while the owner asks the authority under section 173A to deal cleanly with other requirements which no longer serve a planning purpose.

 

When should a planning consultant and enforcement solicitor work together?

 

The planning consultant’s job is often to show the authority why an alternative scheme is lawful, workable and still addresses the planning harm. That can mean analysing the notice and appeal decision, preparing drawings, dealing with planning policy, setting out the alternative compliance route and negotiating with the enforcement team.

A planning enforcement solicitor becomes particularly important where the compliance period has expired, prosecution is threatened or underway, the legal meaning of a requirement is disputed, a section 172A assurance may be needed, the authority’s refusal raises public-law issues, or ownership and conveyancing disputes sit behind the enforcement problem.

Those roles overlap, but they are not interchangeable. Where criminal liability may already exist, planning negotiations should be structured so that a sensible attempt to resolve the site does not accidentally concede a legal point or leave the prosecution position unaddressed.

 

What if the council refuses to use section 173A?

 

Section 173A is discretionary. There is no statutory right of planning appeal simply because the authority refuses to relax or withdraw the notice, and the original appeal right is not revived. A public-law challenge may be possible in an exceptional case where the decision is legally flawed, but that is a matter for a solicitor rather than a substitute appeal on the planning merits.

A related planning application may have its own right of appeal if it is refused. Our general guide to planning appeals explains those routes. The key is to keep the two decisions separate: refusal of an application and refusal to exercise section 173A are not the same legal event.

If the notice is already in force, continue working from the actual compliance obligations unless and until the authority has clearly changed them. An unanswered section 173A request is not permission to ignore the notice.

 

Section 173A enforcement notice legislation and sources

 

The main sources are below. The legislation links go directly to legislation.gov.uk.

• Town and Country Planning Act 1990, section 173A, variation and withdrawal of enforcement notices
• Town and Country Planning Act 1990, section 172A, assurance as regards prosecution for a person served with a notice
• Town and Country Planning Act 1990, section 174, enforcement appeals including grounds (f) and (g)
• Town and Country Planning Act 1990, section 179, offences for non-compliance
• Town and Country Planning Act 1990, section 180, effect of subsequent planning permission
• Town and Country Planning Act 1990, section 181, continuing effect of an enforcement notice after compliance
• GOV.UK Planning Practice Guidance: enforcement and post-permission matters
• Planning Inspectorate: Enforcement notice appeals procedural guide for England
• Pathfield Estates Ltd v London Borough of Haringey [2023] EWHC 1790 (Admin), approved judgment

Other Enforcement Sections

 

 

 

Section 173A Enforcement Notice Page Updated: 26th August 2026