You have discovered that something at your property may not have received planning permission.
Perhaps the local Council has contacted you about an extension. Perhaps a buyer’s solicitor is asking about an outbuilding. Or perhaps your business has occupied a site for years, but nobody can find the original planning permission.
Two possible solutions are mentioned: a lawful development certificate and retrospective planning permission.
They are not interchangeable.
A lawful development certificate establishes whether the specified development or use is already lawful—or, for proposed development, would be lawful. A retrospective planning application asks the council to grant permission for development that has already taken place.
Before paying for either application, establish which question your property actually needs answered.
What is the difference?
Lawful development certificate:-
Asking the Council whether the development or use is lawful
Council makes decision based on law, facts and evidence
has nothing to do with the reasonableness of the development or the Council’s planning policy
doesn’t grant planning permission but confirms the development or use lawful?
Retrospective Planning Permission
Asking the Council whether planning permission should be granted for what has already happened.
Council makes decision based on its planning merits
its acceptability and reasonableness by applying planning polciy is the central question.
grants planning permission
The distinction matters because a convincing argument about good design cannot replace missing evidence in a certificate application. Equally, the fact that a building exists does not mean a retrospective application must be approved.
For a fuller explanation of applying after work has taken place, read Retrospective Planning Permission: What If You’ve Already Built?
Which type of lawful development certificate do you need?
There are two main types relevant to ordinary planning matters.
A certificate for existing development or use
This concerns something that has already happened: building work, a use of land or buildings, or an activity involving a planning condition. It is commonly called an existing lawful development certificate or CLEUD, and the application is made under section 191 of the Town and Country Planning Act 1990.
A certificate for proposed development or use
This concerns something you intend to do. It is commonly called a proposed lawful development certificate or CLOPUD, under section 192. GOV.UK
A proposed certificate can provide formal confirmation that an extension would fall within permitted development rights. Those rights grant permission for specified development subject to the relevant limitations and conditions; a separate planning application is not always necessary. (GOV.UK)
For householders at that earlier stage, our guide explains whether you need planning permission for an extension and what to check before paying for drawings.
Does the four-year or ten-year rule make development lawful?
Potentially—but a building’s age is not enough to settle the question.
In England, the enforcement time limits changed on 25 April 2024.
For building works substantially completed before that date, and an unauthorised change of use to a single dwellinghouse occurring before that date, a four-year period can remain relevant. For those categories occurring on or after that date, the period is generally ten years. Other breaches, including other material changes of use and breaches of condition, generally have a ten-year period.
Exceptions can apply, including cases involving previous enforcement action or deliberate concealment. (GOV.UK)
Our starting point would therefore be to identify precisely what needs to be established: the building’s construction, its use, compliance with a condition or several separate matters.
“It has been there for years” is the beginning of an investigation, not the conclusion.
What evidence do you need for a lawful development certificate?
For an existing use claim, the applicant must establish the case on the balance of probabilities: broadly, that the claimed position is more likely than not.
Government guidance explains that sufficiently precise and unambiguous applicant evidence can justify a certificate where there is nothing that contradicts it or makes the account less probable. The council’s lack of contrary evidence does not remove the need to put forward a properly evidenced case. (GOV.UK)
Depending on the issue, useful material can include dated photographs, invoices, tenancy records, utility records and statements from people with direct knowledge of the property. (Bradford Council)
I would organise that material around the question each document can actually answer:
Historic photographs - What is visible, where it is located and whether the date is reliable.
Building invoices and records - What work was undertaken and whether the documents identify the relevant building.
Occupation or business records - Which premises they concern and what activity they demonstrate.
Witness statements or statutory declarations - What the person knows first-hand, the relevant period and how specifically they can describe it.
A statement explaining the facts, supported by plans and evidence from people with personal knowledge, can help make the case understandable. (Guildford Borough Council)
The objective is not the largest possible bundle of documents. It is a clear account supported by evidence that addresses the actual legal question.
Do not guess dates to make a chronology appear complete. Identify uncertainty so that it can be investigated.
Three examples of how the route can differ
These are illustrative examples, not claims about completed Fellpath projects.
1. An extension that complied with permitted development rights
Imagine a homeowner has completed an extension without making a planning application.
A review establishes that the work complied with the relevant permitted development rights and all necessary requirements.
The question is then how to demonstrate that position; not automatically how to seek retrospective permission. An existing lawful development certificate may be worth considering as formal confirmation. (Northumberland County Council)
2. An old outbuilding with a newer residential use
Imagine an outbuilding was constructed in 2015 but only began being used as a separate home in 2025.
A photograph from 2015 might show that the structure existed. It cannot, by itself, establish that the separate residential use also existed then.
We would investigate the building and its use separately before recommending a certificate application. That distinction follows from the separate enforcement rules for building operations and changes of use. (GOV.UK)
3. A recent business use that needs permission
Imagine a business has recently started using land in a way that requires permission, with no existing authorisation covering it.
A certificate cannot grant the missing permission simply because the business provides employment or the owner considers it harmless.
The planning merits may instead need to be assessed through a retrospective application, potentially alongside changes to the operation. (Northumberland County Council)
The useful question is not “Which application is easiest?” It is “Which application fits the facts?”
Is a lawful development certificate cheaper?
Not necessarily.
There are separate costs to consider: the council’s application fee, the work needed to prepare the case, and any drawings or specialist input.
Council application fees
For existing development or use, the certificate fee is generally the same as the equivalent planning application fee. For proposed development or use, it is generally half the equivalent planning fee.
For illustration, the published England fee schedule applying from 1 April 2026 lists £548 for a standard alteration or extension to a single dwellinghouse. On that basis, the corresponding existing development certificate would generally be £548, while a proposed-development certificate would be £274. Different categories, exemptions and additional submission charges can affect the amount payable. (Bradford Council)
Check the correct category before budgeting. A proposed certificate’s lower fee does not make it the appropriate application for work that has already been completed.
Professional fees and supporting work
At Fellpath Planning, our standard consultancy rate is £175 plus VAT. We explain the proposed scope and charging basis before you instruct us. Fellpath Planning
For a certificate application, our work might include investigating the history, analysing and preparing the evidence, preparing the planning law argument and responding to council questions.
For retrospective permission, the work might instead focus on whether the development is acceptable based on the local plan and national planning policy and what drawings, amendments or technical evidence are needed.
I would not quote a reliable total without understanding those tasks. A clear permitted-development assessment and a disputed history stretching across several owners require different amounts of work.
Our article How Much Does a Planning Consultant Cost—and Is the Cheapest Quote Really the Best Value? explains how to compare scope as well as price.
How long does a lawful development certificate take?
The usual decision period is eight weeks after a valid application, although a longer period can be agreed. If the council fails to determine the application within the applicable period, an appeal route may be available; it is not an automatic approval. Planning Portal
Your programme also needs to allow for preparing the submission. I would identify missing records and drawings before treating any anticipated decision date as dependable.
For the distinction between an application’s formal timetable and the whole project, read How Long Does Planning Permission Really Take?
Can neighbours object to a lawful development certificate?
A certificate is not decided by weighing up whether neighbours like the development.
There is no statutory requirement for the usual third-party consultation, although the council can seek relevant evidence. A neighbour’s dated records or first-hand knowledge could matter to whether a claimed use has occurred. Their dislike of the design is a different matter and does not determine lawfulness. Worcester City Council
We would therefore distinguish factual evidence from opinions about whether the development should have been allowed.
Will a certificate help when selling a property?
It can.
A lawful development certificate may help answer a purchaser’s questions about the planning status of specified works or a use. Planning Portal specifically identifies its potential value in responding to enquiries from buyers and their legal representatives. Planning Portal
However, a certificate is not a general approval of every aspect of the property.
Building Regulations, listed building requirements and other licensing or regulatory obligations remain separate. A certificate also cannot be treated as permission for an unassessed future change. GOV.UK
Our recommendation would be to identify exactly what the buyer’s adviser needs clarified before commissioning an application.
What happens if the certificate is refused?
Read the reasons carefully.
A refusal does not necessarily settle that the development is unlawful. It may mean that the evidence submitted was insufficient. Further evidence could support another application, or there may be grounds to appeal. GOV.UK
The next step should follow the actual problem.
Is an important date unsupported? Do the plans fail to identify the land being claimed? Does the council disagree with the interpretation of the law? Or does the evidence show that the certificate route is not available?
An appeal against a certificate refusal still concerns lawfulness. It is not an opportunity for the Inspector to grant planning permission because the development seems acceptable. GOV.UK
What changes if the council has already started enforcement action?
The documents and deadlines become an immediate priority.
A formal enforcement-notice appeal must be received before the notice takes effect. Do not assume that preparing a certificate or retrospective application extends that deadline. GOV.UK
An enforcement notice or breach of condition notice already in force can also prevent a certificate being granted where the claimed development would contravene its requirements. GOV.UK
There is another reason to assess the sequence carefully: a related retrospective application can restrict a later enforcement appeal seeking planning permission on ground (a). (GOV.UK)
Before choosing an application, understand how it fits with any existing notice.
Our guides explain what to do after receiving a planning enforcement letter or notice and the deadlines, grounds, costs and alternatives when appealing an enforcement notice.
Do you need a planning consultant to apply?
Not in every case.
You can make a certificate application yourself. Professional advice may be useful where the facts or legal position are complex, but appointing a consultant is not a requirement for every application. Planning Portal
I would particularly recommend an initial assessment where the history is disputed, records are incomplete, building work and changes of use have occurred at different times, or formal enforcement action is underway.
That assessment should help you decide whether further expenditure is justified. It should not automatically lead to a full application.
How Fellpath approaches these decisions
My planning career began in enforcement at Copeland Borough Council (Now Cumberland Council), before further local government roles and a move into housebuilding. That background informs how I assess planning problems today. You can read more about my experience and why I established Fellpath. Fellpath Planning
I would start by asking what you need to achieve, then establish what has happened, what evidence exists and which route offers a realistic way forward.
Sometimes that means demonstrating lawfulness. Sometimes it means seeking permission or investigating changes. Sometimes the sensible advice is not to spend more money on a case that the available evidence cannot support.
Fellpath provides planning consultancy in Cumbria and planning enforcement support across England. Our planning enforcement advice service explains the support available and how we agree the initial work. Fellpath Planning
Find out which route fits your property
Before committing to an application, send us the property address, a brief explanation of the building or use, the relevant dates and any council correspondence.
Tell us what you are trying to achieve and highlight any deadline.
We will explain whether we can help, what the initial assessment would involve and how it would be charged before you instruct us.
Ask Fellpath about a lawful development certificate or retrospective planning application
The first task is not to fill in a form. It is to establish which question needs answering.
This article provides general information about planning in England, checked on 10 October 2026. The appropriate route depends on the property, evidence and applicable law. An enquiry does not extend a deadline or mean that Fellpath has accepted an instruction.