By Michael Kalam
Founder, UK Planning Gateway

• Reviewed by a planning professional with 15+ years’ experience
• Based on published Local Planning Authority requirements where relevant
• Designed for architects, architectural technologists and planning consultants

Every senior architect, planner and Chartered Technician knows the message:

“Your application has been deemed invalid.”

Most of the time, that is not a design problem. It is not a question of planning merit, and it is rarely about professional judgement. It is a failure of submission alignment: the application does not yet meet the requirements needed for a valid application, so the authority cannot move cleanly into registration, consultation and determination. Planning Practice Guidance is clear that a valid application depends on a completed form, compliance with national information requirements, the correct fee, and provision of local information requirements. It also notes that delays can arise where there are concerns about validity.

The consequences are real and routine. Billable time is lost. Programmes move. Clients need explanations. Internal workflows break sequence. What looks procedural from the outside often feels operationally expensive inside the practice.

Recent commentary from No5 Barristers’ Chambers is a useful reminder that validation is not a procedural nicety. In its “Solid foundations” series, No5 notes that an LPA has no discretion to determine an invalid application and that doing so can leave the resulting position open to judicial review challenge.

That legal dimension matters, but invalidation is not primarily experienced as a legal event inside practice. It is experienced as operational failure at the point where regulated requirements meet real-world submission assembly.

Why it happens so often

National application forms are standardised. Validation requirements are not.

In England, Planning Practice Guidance allows local planning authorities to request additional supporting information through a formally adopted and up-to-date local list, but only where the information is reasonable in light of the nature and scale of the proposal and relevant to a material planning consideration. In Wales, long-standing government guidance similarly provides for local validation requirements and stresses that they should be clear, justified and proportionate.

In practice, that means each authority maintains its own working expectations, often including:

• local list documentation and guidance notes
• trigger documents linked to matters such as heritage, flood risk, biodiversity, transport, noise or trees
• authority-specific requirements about how plans, certificates and supporting material are presented
• document expectations that change over time as policy, casework and local working practice develop

That variation is not theoretical. Published local lists routinely set out detailed combinations of national requirements, local requirements and supporting material needed to avoid invalidation. For example, Harrow’s local validation checklist states that a valid application depends on the correct form, fee, national information requirements, and any additional information required by the authority’s local list. Welsh Government guidance similarly gives examples of additional documents that may be required, including biodiversity survey work, flood consequences assessments, transport assessments and tree surveys in the relevant circumstances.

The professional obligation is clear: applicants must comply with published requirements. The structural problem is that there is no single governing pre-submission standard that makes compliance predictable across authorities.

The real cost of submission volatility

An invalid application does not simply pause a project. It often triggers a round of corrective administration:

• identifying the precise cause of invalidity
• rechecking the authority’s published requirements
• amending forms, plans or certificates
• reissuing or renaming documents
• re-uploading material
• explaining the position internally and to the client

The less visible cost is reputational. Repeated non-alignment with published requirements can affect how a practice is perceived by clients and, over time, by authority teams who repeatedly receive poorly assembled packs.

This is why invalidation should not be dismissed as a minor administrative inconvenience. It is a sign that submission control has broken down before determination has even begun.

The missing layer: pre-submission control

What the planning system still lacks is a dependable pre-submission control layer that sits before authority intake and governs whether a pack aligns with published validation requirements before it enters the formal process.

That is the problem space UK Planning Gateway is trying to address. The aim is not to replace planning judgement or professional coordination. It is to introduce more structure into the preparation stage so that published requirements, trigger documents, file control and submission logic are checked in a more disciplined way before the application reaches the authority.

In practical terms, that kind of pre-submission layer is concerned with process controls such as:

• aligning the submission pack to the authority’s published checklist and local list
• surfacing likely trigger documents before upload rather than after invalidation
• structuring file naming and packaging more consistently
• applying checks before material enters the authority workflow
• retaining a record of what was prepared and against which published requirement set

The point is not automation for its own sake. It is tighter governance of preparation.

From reaction to controlled submission

Historically, validation has often been treated as reactive:

Submit. Wait. Receive invalidation. Correct. Resubmit.

That sequence has become normalised, but it should be understood as a failure mode rather than a standard.

A more controlled submission model changes the sequence by bringing checks forward. The objective is not simply speed. It is predictability. Predictable validation, predictable workflow sequencing and more reliable professional delivery.