AI declarations enter planning application validation

An AI declaration explains whether AI helped prepare a planning submission and, where required, identifies the material involved and how it was checked. North Norfolk has included AI evidence in its local validation list, Slough asks applicants to explain substantive AI use, and Mid Devon publishes declaration wording alongside consultation material whose formal outcome remains unclear.

Those examples do not establish a new national requirement. Whether a council can refuse to validate an application because a declaration is missing depends on the application procedure, its published requirements and the legal tests which apply. The distinction matters for householders, developers and the consultants preparing their submissions.

What councils ask for in an AI declaration

The requirements differ. Some address evidence produced with AI. Others ask applicants to confirm whether AI was used at all. We checked the published council documents on 17th September 2026.

North Norfolk’s local list follows consultation between 16th October and 27th November 2024. Its matrix covers 12 application types, including householder applications and non-material amendments. The matrix has no separate columns for lawful development certificates or tree applications, so it should not be treated as evidence that those procedures are included.

North Norfolk asks for affected content and altered visual material to be identified and for responsibility for accuracy and lawful use to be confirmed. Routine spelling and grammar functions are excluded. Its AI declaration template asks whether generative AI has or has not been used. That is broader than the trigger in the guidance. Applicants should check which requirement the council is actually applying.

Slough’s AI declaration guidance asks for a short explanation for each affected document, covering the tool, its purpose, checks and responsibility. Its general local list was adopted on 1st January 2026. That date does not, by itself, establish when the AI wording was added or whether it was separately consulted upon.

At Mid Devon, the consultation ran from 12th August to 2nd September 2026. Its published AI guidance now allows a declaration in a planning statement, design and access statement, covering letter or another supporting document. A separate form is optional. It asks whether the content was independently reviewed or verified and who accepts responsibility. However, the closed consultation page still describes a proposed requirement. Publication should not be confused with verified formal adoption.

Can a council require an AI declaration for every application?

There are four separate issues: being transparent about how evidence was prepared, following the Planning Inspectorate’s requirements, complying with a council’s local list and satisfying the statutory requirements for a valid application. They should not be rolled into one rule.

For ordinary applications for planning permission in England, section 62 of the Town and Country Planning Act 1990 permits local information requirements but limits them. A requirement must not conflict with the development order. It must be reasonable having particular regard to the nature and scale of the proposal, and concern something the authority can reasonably think will be material to its decision.

The Development Management Procedure Order also requires the relevant local information to appear on a list published or republished within the preceding two years. An adopted list does not remove the need to apply those tests to the application in front of the council. Our validation requirements guide explains that framework.

The August 2026 NPPF adds a clear policy expectation. DM1 seeks the minimum information necessary for proposals other than major development. Under DM2, additional local-list requirements should be supported by a development-plan policy requiring a specific further assessment, and should reflect the proposal’s scale and potential impact. Annex C does not introduce an AI declaration. These are current national policies, rather than new wording inserted into section 62.

A council can have a sound reason to question the reliability of particular evidence. An altered site photograph or computer-produced technical analysis could affect an assessment. That does not automatically justify demanding the same declaration on every small application, including a statement confirming that AI was never used.

Minor applications, certificates, amendments and trees

Minor and householder applications for planning permission remain subject to the ordinary statutory tests. Smaller scale does not mean that no supporting information can be required, but it matters to whether the demand is reasonable.

Other submissions have different rules:

• Non-material amendments: an application under section 96A is not an application for planning permission. Article 10 provides its own procedure
• Lawful development certificates: article 39 has a separate validity test and a power to request further information in writing to enable a decision. A general planning-permission checklist is not automatically part of that test
• Tree Preservation Order applications: the statutory requirements and standard form govern. Government guidance distinguishes asking for additional information from having power to require it
• Conservation-area tree notices: these are notices under section 211, with their own requirements and time period

Those distinctions are explained in the government’s amendment guidance, certificate procedure and tree guidance. A local list cannot simply replace those statutory regimes.

We have not identified a reported judgment deciding the legality of an AI declaration requirement itself. Our conclusion is narrower: putting a declaration on a local list does not establish a lawful blanket requirement across every type of application and notice.

What the Planning Inspectorate requires

The Planning Inspectorate’s guidance, updated on 20th February 2026, concerns evidence submitted in proceedings it handles. It asks for disclosure where AI drafts or substantially rewrites text, produces analysis or summaries, alters visual material or creates substantive content. Routine spelling, grammar, formatting and accessibility functions are excluded.

A short statement should identify the tool, explain its use and the checks undertaken, and confirm responsibility for accuracy. It can be included in correspondence or evidence. Professional parties remain responsible for the accuracy and lawfulness of what they submit. Improper use may amount to unreasonable behaviour with costs consequences, depending on the circumstances.

This is a casework disclosure requirement. It does not create a new statutory validity requirement for every application submitted to a local council.

The wider picture

Our search also identified Highland Council’s planning AI guidance, last modified on 11th June 2026. It asks for substantive use to be disclosed, with the tool and checks explained, and says failure to disclose significant use may affect the assessment. We did not establish that this is a formally adopted validation prerequisite. Highland is in Scotland, where the English section 62 and DMPO analysis above does not apply.

These are verified examples, rather than an exhaustive register of every council using AI disclosure wording.

4 AI declaration checks for applicants and consultants

1. Check the right procedure: identify the statutory requirements and the council’s current published list for your submission
2. Keep substantive evidence traceable: record which tools materially contributed, which content was affected and how it was checked
3. Take responsibility: verify sources, measurements, policy references and conclusions before submission
4. Challenge an unexplained validation demand: ask the council for the statutory provision, adopted list entry and application-specific justification

For an ordinary planning application, the validation dispute procedure may help where a local information demand does not meet the statutory tests. It is not a single appeal route for every certificate, amendment or tree notice.

If a disputed requirement is delaying your project, Planning Geek can review the planning position and help prepare a proportionate response. Contact us with the council’s request and the application details.

Prepared: 17th September 2026