A certificate of lawfulness is a council's formal statement that a use or building work is lawful for planning purposes. Section 191 of the Town and Country Planning Act 1990 covers what exists, and section 192 what you propose. In England, ten years is now the enforcement time limit for breaches on or after 25 April 2024.
The certificate is evidence, not permission. It records a fact on a date, in a document a buyer's solicitor, a lender or a neighbour's lawyer can read. Most of the confusion around it comes from the enforcement time limits, which changed in 2024 and now depend on when the work was finished.
Key Takeaways
- Section 191 certifies an existing use or building; section 192 certifies a proposal. Both are decided on lawfulness, never on planning merit.
- The test is evidence "on the balance of probability" that is "sufficiently precise and unambiguous", and the burden sits with the applicant.
- In England, section 171B now gives ten years for operational development and for a change of use to a single dwelling. Breaches that occurred or were completed before 25 April 2024 keep the old four years.
- A certificate covers planning law only. Building regulations and listed building consent still apply.
- Applying is optional. A certificate is worth the council fee where someone else needs proof.
What is the difference between a section 191 and a section 192 certificate?
A section 191 certificate says an existing use, building operation or breach of condition is lawful because no enforcement action can now be taken. A section 192 certificate says a proposed use or operation would be lawful if started on the day you applied. The first looks back; the second looks forward.
The existing-use route is in section 191. A use or operation is lawful if enforcement can no longer be taken, either because it never needed permission or because the time limit has passed, and it breaches no enforcement notice in force. Once issued, its lawfulness is "conclusively presumed".
The proposal route is in section 192. Here the council must issue a certificate if it is shown that the proposal "would be lawful if instituted or begun at the time of the application". That protection is conclusive unless there is a material change in a relevant matter before work starts. The Planning Practice Guidance gives an Article 4 direction as an example.
That example is the strongest practical reason to apply early. If a council makes a direction removing a permitted development right next month, a section 192 certificate you already hold for work under that right is unaffected, provided nothing about the proposal changes.
What evidence does the council need for a certificate?
The council needs enough precise factual evidence to be satisfied, on the balance of probability, that the use or work is lawful. The burden of proof sits with the applicant. For an existing use, if the council has no contrary evidence of its own, it should not refuse while yours is precise and unambiguous.
The Planning Practice Guidance says the applicant's evidence must be "sufficiently precise and unambiguous", and that the description must be exact, not just a use class. It adds that planning merits are irrelevant, and that the council has no statutory duty to consult third parties.
For a proposal, that evidence is drawings: existing and proposed plans and elevations, drawn to scale and measured to show the limits of the right are respected. For something already built, it is dated material that fixes when and what. Typical examples are dated photographs, building control records, tenancy agreements, utility or council tax records, and statements from people who were there. A single undated snap proves little. Measured drawings of the building as it stands are what let the council compare the work with the right it relies on.
The same guidance warns that a certificate can be revoked where it relied on a false or misleading statement or on withheld information, and that giving false information to obtain one is an offence carrying up to two years' imprisonment. Do not stretch the dates.
How long before building work becomes immune from enforcement?
In England, building, engineering or other operations are immune from enforcement ten years after substantial completion, and so is a change of use to a single dwellinghouse, ten years from the breach. That applies where the work was completed or the breach occurred on or after 25 April 2024. Earlier breaches keep four years.
This is the biggest change to the old "four-year rule and ten-year rule" shorthand. Section 171B now gives ten years in England for both operational development (subsection 1) and a change of use to a single dwelling (subsection 2), after the Levelling-up and Regeneration Act 2023, section 115 rewrote them. Wales kept four years. Any other breach, such as most changes of use, was already ten years under subsection 3.
The date it started is set by regulation 3 of SI 2024/452: section 115 came into force on 25 April 2024. Regulation 5 then says the new limits do not apply where the operations were substantially completed, or the change of use occurred, before that day.
| Breach | Finished or occurred before 25 April 2024 | On or after 25 April 2024 |
|---|---|---|
| Building or other operations | Four years from substantial completion | Ten years from substantial completion |
| Change of use to a single dwellinghouse | Four years from the breach | Ten years from the breach |
| Any other breach of planning control | Ten years | Ten years |
A worked example shows the effect. A rear extension substantially completed on 1 March 2022 without permission was still on the four-year clock when the law changed, so it passed that point in March 2026. The same extension finished on 1 June 2024 cannot reach immunity until June 2034. Two identical extensions can therefore have very different positions.
Concealment is not rewarded. Section 191(3A) stops the time limit being treated as expired while a planning enforcement order is available, applied for or in force. If you hid the work, an expired clock may not be the end of it.
When is a certificate of lawfulness worth having?
A certificate is worth having when someone other than you needs proof, or when the right you rely on might be removed. Selling, remortgaging, a neighbour dispute, or an Article 4 direction on the way are the common cases. If none of these applies, you are not obliged to apply, and for clearly permitted work it may not be necessary.
The Planning Practice Guidance says anyone can apply. Nothing in sections 191 or 192 makes an application compulsory, and the checker on this site will tell you honestly if your project needs nothing at all. Our permitted development checker is free, ungated and does not tilt toward the paid route.
Where a certificate does earn its fee:
- A sale. A buyer's solicitor asks why an extension has no permission. A section 191 certificate answers it in one document. If the extension went up under the larger-home route, the prior approval guide explains how that works.
- A permitted development proposal. A section 192 certificate fixes the right at today's rules. See the guide to loft conversions under permitted development for the limits.
- An unconsented conversion that has aged out. An existing-use certificate proves the clock has run. The garage conversion planning guide explains when a garage change needs consent.
- A small HMO that predates a direction. Evidence of lawful C4 use can matter once an Article 4 direction arrives. See our HMO planning guide.
A certificate does not replace the other regimes. The Practice Guidance is explicit that it covers planning legislation only, so building regulations, listed building consent and other licensing still apply.
What does a certificate of lawfulness cost?
The council charges a fee set nationally, and it is paid to the council, not to us. For a proposed use or operation under section 192 it is £274. GOV.UK says that is half the planning application fee, while an existing-use application costs the same as the equivalent permission.
Our fee is separate. A certificate of lawfulness from Fixed Fee Plans is from £950, built from a measured survey at £150, existing and proposed drawings at £700, and submission as your agent at £100. The council's fee is never bundled into that figure, and the receipt goes to you.
The price is a floor rather than a fixed figure, which is why it reads "from". The price list always carries the current figure and what it covers.
Frequently asked questions
Is a certificate of lawfulness the same as planning permission?
No. It records that something is, or would be, lawful. Planning permission grants a right. The council does not weigh merit when deciding a certificate.
Does the ten-year rule apply to my 2021 extension?
Not if it was substantially completed before 25 April 2024. Regulation 5 of SI 2024/452 keeps the four-year period for earlier operations.
Can the council refuse if I have no paperwork?
Yes. It must refuse unless the evidence is precise and unambiguous on the balance of probability. Missing paperwork can be replaced by statements and dated records, but gaps carry risk.
Do I need a certificate for permitted development?
Not by law. It is optional proof, useful for a sale, a lender, or fixing a right before a direction removes it.
Sources
All retrieved 10 October 2026.
- Town and Country Planning Act 1990, section 191 (existing use or development): https://www.legislation.gov.uk/ukpga/1990/8/section/191
- Town and Country Planning Act 1990, section 192 (proposed use or development): https://www.legislation.gov.uk/ukpga/1990/8/section/192
- Town and Country Planning Act 1990, section 171B (time limits for enforcement), revised text current to 10 October 2026: https://www.legislation.gov.uk/ukpga/1990/8/section/171B
- Levelling-up and Regeneration Act 2023, section 115 (time limits for enforcement): https://www.legislation.gov.uk/ukpga/2023/55/section/115
- The Planning Act 2008 (Commencement No. 8) and Levelling-up and Regeneration Act 2023 (Commencement No. 4 and Transitional Provisions) Regulations 2024 (SI 2024/452), regulations 3 and 5: https://www.legislation.gov.uk/uksi/2024/452/regulation/5 and https://www.legislation.gov.uk/uksi/2024/452/pdfs/uksi_20240452_en.pdf
- Planning Practice Guidance, Lawful development certificates: https://www.gov.uk/guidance/lawful-development-certificates
- GOV.UK, Fees for planning applications: https://www.gov.uk/guidance/fees-for-planning-applications