Aipedia: Planning consultants

Planning Inspectorate AI declaration explained

Aipedia, by the Apex broking team · Last reviewed 2026-10-27

Anyone submitting evidence to the Planning Inspectorate must declare intentional AI use that drafts, summarises, analyses or creates images, and confirm they take responsibility for accuracy. For planning consultants this is the main AI rule in practice, and getting it wrong can lead to costs.

Part of: AI in Planning consultants

In short

The Planning Inspectorate guidance "Use of artificial intelligence in casework evidence" was first published on 6 September 2024 and updated on 23 September 2026 with changes to how AI use is declared. It covers appeals, applications and examinations in England and Wales. A declaration must say AI was used, what for and how, with paragraph or section references, describe the checks made, and confirm responsibility for accuracy. Each expert declares for their own documents. Spellcheck and formatting tools are exempt. Improper AI use may be unreasonable behaviour leading to a costs award.

Who publishes what

Planning consultants have no statutory regulator, so the AI rules that bite come from the body that receives their evidence. The table summarises the position as at October 2026.

Body	Publication	Status	Dates
Planning Inspectorate	Use of artificial intelligence in casework evidence	Guidance setting how evidence must be presented; non-compliance can support a costs award	Published 6 September 2024; updated 23 September 2026 (declaration changes) and 29 September 2026 (Welsh content)
RTPI	Code of Professional Conduct	Binding on members; no AI-specific clause found	In force 1 February 2023
RTPI	Blog: Professional standards and ethical uses of AI	Commentary; content not confirmed, not guidance	17 August 2026
High Court	Ayinde v Haringey; Al-Haroun v QNB [2025] EWHC 1383 (Admin)	Judgment; leading warning on AI-fabricated authorities	6 June 2025

The full text is on GOV.UK: Use of artificial intelligence in casework evidence.

Who the guidance applies to

The guidance applies to everyone who submits material in Planning Inspectorate casework: appellants, applicants, local planning authorities, interested parties and professional parties such as planning consultants and chartered surveyors. It covers appeals, applications and examinations, including NSIP examinations (see AI in NSIP examination submissions). It applies in England and Wales.

Local planning authorities are not exempt. If an LPA uses AI to summarise representations, it must still provide the original documents, so a summary never replaces the underlying evidence.

What must be declared

You must declare where AI has been intentionally used to:

draft text or substantially rewrite it;
produce a summary or analysis of documents, data or responses;
generate or alter images or videos, including visualisations and photomontages;
create any other content beyond formatting.

The test is what the AI did, not what the tool is called. A grammar checker is outside scope; using the same software to rewrite a section of a proof is inside it. For imagery, see AI visualisations and photomontages.

How to word the declaration

Following the September 2026 update, a declaration should:

state that AI was used;
say what it was used for and how, giving paragraph, section or appendix references, and for images, which parts were generated or altered;
describe the checks made on the output;
confirm that the author takes responsibility for the accuracy of the content.

It can go in a covering letter or within the statement of case or proof of evidence. An illustrative form of words: "An AI assistant was used to produce a first draft of section 4 and the summary of policy at Appendix B. I checked every policy extract against the adopted plan and every appeal reference against the published decision. I take responsibility for the accuracy of this proof."

Per-expert declarations and exemptions

Each expert should declare for their own documents. The Inspectorate says a single catch-all declaration is unlikely to be sufficient. If a planning consultant coordinates an appeal with heritage, transport and landscape witnesses, each proof needs its own accurate declaration, and the consultant cannot vouch for checks other experts made.

Spellcheck, grammar, formatting and accessibility tools do not need to be declared. Nor does incidental use that creates no content. If in doubt, declaring is the lower-risk course.

The golden rule and costs risk

The guidance describes a "golden rule" of responsible use. It warns that AI can create fake representations, evidence, text and images, and it discourages AI cartoons or exaggerated illustrations of a proposal.

Two consequences follow. Inspectors may ask for clarification about AI use. And improper AI use may be treated as unreasonable behaviour leading to an award of costs. For an appellant represented by a consultant, that means a costs order against the client, who may then look to the consultant. Apex's planning consultants PI claims examples show how such disputes develop. No costs decision specifically citing AI misuse had been found as at October 2026.

What it means for practice and PI

In practice, consultants should build the declaration into document sign-off, keep a note of which paragraphs AI touched and what was checked, and brief every expert on the per-expert rule. A false or incomplete declaration is itself a professional conduct risk under the RTPI Code of Professional Conduct, which applies to RTPI members whether or not AI is mentioned.

For PI, a negligent submission that loses an appeal is usually covered as civil liability, subject to the wording. A costs award is a harder question: see AI-linked costs awards and PI. Note any declaration failure that could lead to a claim as a circumstance under your policy.

How Apex helps

Apex arranges PI for planning consultants, and a broker can review how your policy treats AI-assisted appeal work and costs exposure. Read the planning consultants PI guide or return to the AI in planning consultancy overview.

Sources

Frequently asked

When did the Planning Inspectorate AI guidance change?

It was first published on 6 September 2024. It was updated on 23 September 2026 with changes to how AI use should be declared, and on 29 September 2026 to add Welsh content. Check the GOV.UK page before each submission, as the guidance can change again.

Can one declaration cover a whole appeal team?

Unlikely. The guidance says each expert should declare for their own documents and that a single catch-all declaration is unlikely to suffice. Each witness knows what they used AI for and what they checked, so each should sign their own declaration.

Do I need to declare using a grammar checker?

No. Spellcheck, grammar, formatting and accessibility tools need not be declared. If the same tool rewrote substantial passages or produced a summary, that use falls within the guidance and should be declared.

What happens if AI use is not declared?

An inspector may ask for clarification. If AI use was improper, for example producing fake material, it may be treated as unreasonable behaviour and lead to an award of costs against the party. It may also raise professional conduct questions for RTPI members.

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Apex Insurance Brokers Limited is authorised and regulated by the Financial Conduct Authority. Registered in England and Wales, company number 07014570. This page is general information about how AI is used in the profession and how insurance may respond. It is not legal, regulatory or insurance advice on your circumstances, and it does not guarantee that cover will be available or on what terms.