Lawful Development Certificates and Certificates of Lawfulness

The two certificates, and which one you need

• A certificate of lawfulness of existing use or development, under section 191 of the Town and Country Planning Act 1990, covers work already carried out or a use already established. Uses and operations are lawful if no enforcement action may then be taken against them. (legislation.gov.uk, September 2026)

• A certificate of lawfulness of proposed use or development, under section 192, covers work you have not started. If the council is satisfied the work would be lawful, it must issue the certificate. (legislation.gov.uk, September 2026)

• Once a section 192 certificate is in force, the lawfulness of the work is conclusively presumed unless there is a material change before the work begins. That is a stronger legal position than an informal email from a planning officer. (legislation.gov.uk, September 2026)

When you actually need one

• Selling is the usual trigger. A buyer's solicitor asks for evidence that an extension, loft conversion or outbuilding was lawful, and permitted development does not produce any paperwork of its own. The certificate is the paperwork.

• The second trigger is doubt before you build. Where a project sits close to a permitted development limit, a section 192 certificate converts an opinion into a decision, before you have spent money on it.

• The third is work already done without permission that is now old enough to be immune from enforcement. In England no enforcement action may be taken over unauthorised building work after ten years beginning with the date the operations were substantially completed. (legislation.gov.uk, September 2026)

• In Wales that period is still four years from substantial completion, so the widely repeated four-year rule now applies only in Wales, not in England. (legislation.gov.uk, September 2026)

What it costs

• A lawful development certificate for an existing use or operation costs £309 in England. (Planning Portal, April 2026)

• For comparison, a full householder planning application costs £548, and a prior approval application for a larger home extension costs £249. (Planning Portal, April 2026)

• The certificate is decided on evidence and law, not on planning merit. The council is not deciding whether it likes the development; it is deciding whether the development is lawful. That is why the quality of the evidence you submit matters more than the design.

What it is not

• It is not planning permission, and applying for one does not regularise something unlawful. If the work needed permission and the time limit has not passed, the answer is a retrospective application, not a certificate.

• It is not building regulations approval either. A certificate confirms the planning position and says nothing about whether the structure meets building control standards.

Common questions

What is the difference between a lawful development certificate and planning permission?

Planning permission grants the right to build something. A lawful development certificate confirms that the right already exists, either because permission was never needed or because the enforcement time limit has passed. If you need permission and do not have it, a certificate cannot fix that.

How much does a certificate of lawfulness cost?

£309 in England for an existing use or operation, under the fee schedule in force from 1 April 2026.

Can I get a certificate for an extension built without permission?

Yes, if it is now immune from enforcement. In England that means ten years from substantial completion of the building work. You will need evidence of the date, such as dated photographs, invoices or utility records.

Sources