Liability when one party writes and another submits

A technical report prepared for one party and submitted by another is one of the most common arrangements in planning, and one of the least examined. The consultant who wrote the bat survey was appointed by the landowner. The application is made by the developer who bought the site. The council validates the application without asking who owed a duty to whom, because that is not its job. If the survey turns out to be wrong, the question of who can sue whom is decided by contract and by the law of negligence, and the answer is frequently that the person who relied on the report has no claim at all.

Who owes a duty to whom

Start with the appointment. A consultant owes a contractual duty to the client who appointed them, on the terms agreed, for the scope described. That duty is usually to exercise the reasonable skill and care of a competent professional in the relevant discipline.

Outside the contract, a duty in negligence can arise, but not automatically. The principle running through the case law since Hedley Byrne in 1964 is assumption of responsibility: has the professional, expressly or by conduct, assumed responsibility to this particular person for this particular purpose, and has that person relied on the advice reasonably.

A report addressed to one client, with a scope defined for that client's project, does not create a duty to everyone who later reads it. Courts have been reluctant to extend liability to an indeterminate class of readers, and a report that circulates through a data room is close to the definition of an indeterminate class.

Scope matters as much as identity. Even where a duty exists, the loss recoverable is generally limited to the consequences of the matter the professional was retained to advise on, rather than every loss that follows from the transaction.

Reliance by someone who did not commission the report

Four situations come up repeatedly.

• The land is sold, and the buyer submits reports commissioned by the seller.
• A developer submits a report addressed to a previous applicant on the same site.
• A joint venture changes structure, and the applicant entity is not the appointing entity.
• A report prepared for one scheme is submitted in support of a materially different one.

In each case, the person submitting has the document but may have nothing else. No contract, no assumption of responsibility, and often no way of knowing whether the consultant's insurance is still in place.

The uncomfortable part is that the report may be perfectly good. The exposure is not about quality. It is about who bears the loss if a survey misses something, the permission is quashed or the scheme has to be redesigned.

Reliance letters and what they change

A reliance letter is a short agreement under which the consultant extends a duty of care to a named third party for a stated purpose. It is the standard fix, and the fee for one is trivial against the exposure it covers.

What a well-drafted one does:

1. Names the beneficiary precisely, including group companies if that is intended.
2. States the purpose for which reliance is permitted, such as a planning application for a defined scheme.
3. Confirms the scope and limitations of the original report, rather than silently widening them.
4. Sets a liability cap and states whether it is per claim or in aggregate with the original client's claim.
5. Records the professional indemnity cover the consultant will maintain, and for how long.

Point five is the one people skip. Professional indemnity is written on a claims-made basis, so the policy that matters is the one in force when the claim is made, not when the report was written. A consultant who has ceased trading without run-off cover is a covenant with nothing behind it.

Ask for the reliance letter before you complete on the land, not after the officer asks a question about the report.

Assignment, warranties and a change of owner

Where the whole appointment moves rather than a single report, assignment is the mechanism. Appointments commonly permit a limited number of assignments without consent, often two, and require notice. Read the clause before assuming the benefit travels with the site.

Collateral warranties do a similar job for funders, purchasers and tenants, and usually carry step-in rights allowing the beneficiary to take over the appointment if the original client defaults. On a development with an institutional funder, the warranty package is negotiated at the outset and the planning consultants are frequently forgotten until someone asks for one two years later.

Where sub-consultants sit behind a lead appointment, the chain matters, and who carries the liability when work is sub-let is a question worth answering before the report is commissioned rather than after it is challenged. The same logic drives the choice between one multidisciplinary practice or separate specialists.

Disclaimers and how far they hold

Most technical reports carry a clause saying they are prepared solely for the named client and that no responsibility is accepted to third parties. These clauses generally work, and the courts treat a clear, prominent disclaimer as relevant to whether responsibility was assumed at all.

They are not absolute. Where a term seeks to exclude business liability for negligence causing loss other than death or personal injury, it is subject to a test of reasonableness under the Unfair Contract Terms Act 1977. A disclaimer buried in an appendix, or inconsistent with what the consultant told the third party in a meeting, is on weaker ground than one on the front page.

For a reviewer, the practical reading is different. A disclaimer protects the author. It does nothing for the person relying on the report, which is exactly why the reliance letter exists.

Reports written for a different purpose

Scope creep is the quietest risk in this area. A desk study commissioned to support a purchase decision is not the same document as one prepared to discharge a planning condition. A preliminary tree survey for feasibility is not an arboricultural impact assessment for a specific layout. An ecological walkover for a land promotion is not a survey supporting a licence application.

Submitting a document outside its stated purpose creates two problems at once. The council may find it does not meet the validation requirement, and the consultant will point at their own limitations section if anything goes wrong.

Read the limitations before you read the conclusions. Where the original brief was thin, the report will say so, and that is the section that tells you whether it can carry the weight you are about to put on it. The habit of briefing a specialist properly when the site data is incomplete avoids most of this at source.

Steps before you rely on someone else's work

A short checklist, applied before the report goes into an application:

• Check the addressee and whether your entity is named.
• Check the date, and whether the survey data is still current for the species, the standard or the policy in question.
• Check the site boundary in the report against the red line you are submitting.
• Check the scheme described against the scheme you are applying for.
• Read the limitations, then read them again against your intended use.
• Request a reliance letter, with a cap, a stated purpose and a professional indemnity commitment.
• Confirm the consultant still trades and still holds cover.

Where any of those fails, commissioning a fresh report is usually less expensive than litigating about an old one. Limitation periods for contract and tort claims run from different points, and by the time a defect emerges the useful options have often narrowed.

Reviewers and specialists who take on work on this basis can register through the professional directory, and anyone scoping a project can check which report types carry a professional requirement before deciding whose report to rely on.

This is general guidance, not legal advice; take advice from a qualified lawyer or your insurer on any specific reliance question before acting on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.