Enforcement Time Limits: the 10 Year Rule, and when 4 Years still applies

 

One of the oldest ideas in planning is that a breach of control does not stay enforceable forever. Leave it long enough, and the council loses the power to act – the development becomes immune, and can then be confirmed as lawful. These are the planning enforcement time limits, and they are the most misunderstood corner of the whole system.

They are misunderstood partly because the law changed. For decades people spoke of a “four-year rule” and a “ten-year rule”. In England, that split was swept away on 25th April 2024: there is now a single ten-year limit for almost everything, with the old four-year period surviving only in narrow, transitional circumstances. Get the date wrong and you can badly misjudge whether a breach is safe or still exposed.

This page explains the current position in England, when the four-year rule can still apply, what “immunity” really means, and why time alone is never quite the whole story. It forms part of our planning enforcement guidance. Anyone on the other side of this, wondering whether it is worth reporting something before the clock runs out, should read our guide on how to report a breach of planning control. If you are counting the years because somebody has just reported you, our page on being reported to planning enforcement explains what the council does next.

 

 

 

The position in England today

 

The usual enforcement time limit in England is now ten years, but the former four-year period still applies to the historic breaches covered by the transitional provisions below. The change made by section 115 of the Levelling-up and Regeneration Act 2023 took effect on 25th April 2024 and amended section 171B of the Town and Country Planning Act 1990.

For breaches outside the four-year saving, the starting point depends on what happened:

• Building, engineering, mining or other operations — ten years from substantial completion
• A material change of use or breach of condition — normally ten years from the breach, with the relevant use or breach established throughout the period relied upon

For a change of use to a single dwellinghouse beginning on or after 25th April 2024, the ten-year period applies. A qualifying change before that date remains governed by the saved four-year rule, even where those four years finish afterwards.

Enforcement already taken, concealment and other statutory exceptions can affect the answer. Counting ten years, or four years in a saved case, is therefore only part of the assessment.

 

When the four-year rule still applies

 

The four-year rule has not vanished entirely. The 2024 change is not retrospective, and a transitional provision preserves the old four-year period in two specific situations – broadly, where the relevant event happened before 25th April 2024:

• operational development (building, engineering and the like) that was substantially completed before 25th April 2024
• a change of use of a building to use as a single dwellinghouse where the breach occurred before 25th April 2024

The four years did not have to expire before 25th April 2024. Regulation 5 of SI 2024/452 preserves the old rule by reference to when the operations were substantially completed or the single-dwelling breach occurred. A saved four-year period can continue running after the new legislation commenced.

For example, in The Grange Farm, Stockport appeal, independent residential occupation began on 17th April 2021. The LDC application was made on 22nd October 2025, so the Inspector used 22nd October 2021 as the relevant four-year date, not the council’s suggested 24th April 2020.

The appeal succeeded because the pre-commencement dwelling breach remained within the old rule and the evidence established the required period by the application date. That does not give new unauthorised dwellings created now a four-year route to immunity.

Keep building works and changes of use separate. Substantial completion of conversion works does not, by itself, prove when independent residential occupation began. Where both operations and a material change of use are involved, each needs its own assessment.

 

What “immune” actually means

 

Immunity is a genuinely useful idea, but it is narrower than people hope. Once a breach has run past its time limit, the council can no longer take enforcement action against it – and a use or operation that is immune can be confirmed as lawful through a certificate of lawfulness of existing use or development. That certificate is the formal proof that the development is now beyond enforcement.

Immunity relates to the particular breach established over the relevant period. For a use, the evidence must show genuine continuity, but a short vacancy is not automatically a break in the planning use.

In the Stockport appeal described above, the gap from 17th November to 10th December 2024 between residential occupiers did not interrupt continuity. That was a finding on the evidence in that case, not a fixed three-week allowance for every property. An actual cessation, abandonment or materially different intervening use needs separate assessment.

You must also prove the position on the balance of probabilities. Precise statutory declarations, photographs, bills, tenancy agreements and other contemporary records can be important. The council having no contrary evidence does not remove the applicant’s responsibility to provide a sufficiently clear and coherent case.

An immune use can also slip away in a manner that surprises people. If the land later changes to something else, the immune use is not left sitting there for you to pick up again whenever you choose. Changing back to it is itself a material change of use, and it needs planning permission. The exception is where the council serves an enforcement notice against the later use, because a separate right can then let you return to what went before. Our page on reverting to a previous lawful use explains how that works, and where its limits sit.

Deliberate concealment can defeat immunity

 

There is an important exception for those tempted to run the clock down quietly. Where a breach has been deliberately concealed, the council can apply to a magistrates’ court for a planning enforcement order, which allows action to be taken even after the normal time limit has passed. The provisions sit at sections 171BA to 171BC of the 1990 Act, and they exist precisely to stop someone hiding an unlawful development until it appears immune and then claiming the benefit of the very concealment.

Deliberate concealment and positive deception can prevent reliance on the ordinary time limits. The facts and the applicable legal route matter: the mere fact that a council did not discover a breach is not, by itself, proof of deliberate concealment.

A useful recent example is the George Baldock enforcement appeal, where the Inspector accepted that the residential use had existed for four years but still rejected immunity because of positive deception.

 

What actually stops the clock, and what does not

 

 

This is where people go wrong. The assumption is that any letter from the council freezes the countdown. It does not. The Act sets out a short, closed list of what counts as the council taking enforcement action, and in England it is only these three:

• an enforcement notice
• a breach of condition notice, which carries no right of appeal at all
• an enforcement warning notice, which is the step where the council tells you to apply for permission instead, and which has only counted since 25th April 2024; issuing one also opens a further four year window for the council to come back

Nothing else on that list. So a planning contravention notice, a section 330 notice and even a temporary stop notice all leave the clock running, and so does the whole of a planning enforcement investigation, site visits and warrants included. The council can send you any of them, read your answer, and the countdown carries on the whole time.

There is a second-bite rule that catches people out. If the council has already taken, or tried to take, enforcement action over the same breach, it gets a further window in which to take more, even though the main period has expired. That window is four years, and it was left untouched when the main limits in England moved to ten years, so the two numbers now sit side by side meaning quite different things.

Time is not the only question

 

It is tempting to treat the calendar as the whole answer, but two other things sit alongside it. The first is that listed buildings and protected trees run to different rules – there is no equivalent immunity period for unauthorised works to a listed building, so the passage of time does not make that kind of breach lawful. The second is that the date of the breach, not the date you are counting from today, is what matters, and pinning that date down is often the hard part.

Becoming immune is not a fresh grant of planning permission. Lawfulness relates to the use, operations or breach actually established; it does not automatically erase every other condition or control affecting the property. Later alterations, extensions or changes of use may still require permission.

Our guide to certificates of lawfulness of existing use or development explains how to obtain formal confirmation of the position.

Is there a cost, and can you challenge the council’s view?

 

Working out a time-limit position costs nothing in itself, but proving it usually means an application for a certificate of lawfulness, which carries a fee. Other applications, such as retrospective planning permission if immunity cannot be shown, can carry fees too. Fees are set nationally and change from time to time, so our planning application fees guide explains the current position.

If the council disagrees with you – refusing a certificate, or serving an enforcement notice on the view that the time limit has not run – you are not without recourse. A refused certificate can be appealed to the Planning Inspectorate, and an enforcement notice can be appealed under section 174, one of whose grounds is precisely that the time for enforcement has expired, which is ground (d). Our page on the enforcement appeal grounds sets out what you have to prove to win on it, and where the burden falls. Our guide to planning appeals sets out the routes and deadlines, and our enforcement notices page deals with the notice itself. The one thing not to do is let a deadline slide: enforcement appeal periods are short and unforgiving.

See also our guide to the planning enforcement process.

 

 

 

Enforcement time limits relevant legislation

 

The primary sources below are on legislation.gov.uk. Check the “Changes to Legislation” panel at the top of each page for any amendments not yet incorporated into the revised text.

• Town and Country Planning Act 1990, s171B – time limits (ten years in England from 25th April 2024)
• Levelling-up and Regeneration Act 2023, s115 – the amendment that introduced the single ten-year limit
• Town and Country Planning Act 1990, ss171BA–171BC – planning enforcement orders where a breach has been concealed
• Town and Country Planning Act 1990, s191 – certificate of lawfulness of an existing use or development

Other Enforcement Sections

 

 

 

 

 

 

Enforcement Time Limits Page Updated: 12th September 2026