Certificates of lawfulness for an existing use

A certificate of lawfulness of existing use or development under section 191 of the Town and Country Planning Act 1990 does one thing: it records that a use, an operation or a breach of condition has become lawful because the council can no longer take enforcement action against it. It is not permission. It changes nothing about what happens on the site. What it does is remove the risk, which is why lenders, buyers and insurers ask for one.

And it is decided on evidence rather than on whether anyone thinks the use is a good idea.

What a certificate under section 191 establishes

The application asks the council a legal question. Is this use lawful as at the date of the application, because the time limit for enforcement has expired or because no permission was ever required.

That framing has three practical consequences.

The first is that planning merits are irrelevant. Officers cannot refuse because parking is tight or neighbours are unhappy, and consultation responses only matter where they contradict the factual account.

The second is that the burden of proof sits with the applicant, on the balance of probabilities. You do not have to prove your case beyond doubt. You do have to make it more likely than not.

The third is that the certificate is only as good as the description on it. A certificate describing use as a house in multiple occupation without specifying the number of occupants may be less useful later than one that records the position precisely. Draft the description carefully, because it is the thing you will be relying on in five years.

The time limits that make a use lawful

Immunity comes from the passage of time without enforcement action. The periods have changed, and which period applies depends on when the breach occurred.

Historically, operational development and the change of use of a building to a single dwellinghouse became immune after four years, while other material changes of use and breaches of condition became immune after ten. The Levelling-up and Regeneration Act 2023 moved to a single ten year period for breaches occurring on or after the date it took effect in 2024, with the earlier periods continuing to apply to breaches that had already run their course.

So the first question in any case is when the breach began. Establish that date before deciding which period to argue, and check the current transitional position rather than relying on a summary, because transitional arrangements matter here more than usual.

Continuity is the second question. The period has to run without a break, and a use that stopped for a substantial period and later resumed may have been abandoned or interrupted, which restarts the clock.

Evidence that carries weight with a council

Officers look for records created at the time, for a purpose other than this application.

• Council tax records, and for houses in multiple occupation the licensing history held by the same authority.
• Tenancy agreements, inventories, deposit protection records and rent statements across the period.
• Utility accounts showing separate supplies or occupancy at particular addresses.
• Business rates entries, VAT registration and trading accounts for commercial uses.
• Dated photographs, including images with reliable metadata, and historic aerial imagery.
• Correspondence with the council itself, including previous complaints and the responses to them.
• Electoral roll entries and, for HMOs, the pattern of registered occupants.

Two of these do disproportionate work. Council tax and licensing records because they come from the council's own systems and are hard to argue with, and tenancy agreements because they show occupation by named people on named dates.

Where a use involves plant or fittings, the installation paperwork helps. For a takeaway or hot food use, the extraction system's installation and maintenance records date the operation precisely, and a Ventilation and Extraction Statement describing the installed system is useful evidence of what has actually been in place.

Statutory declarations and who should make them

Declarations are made under the Statutory Declarations Act 1835 before a solicitor or commissioner for oaths. Their weight comes from the knowledge of the person making them.

Choose declarants who saw things rather than people who believe things. The letting agent who managed the property, the neighbour who has lived opposite for twenty years, the contractor who fitted the kitchens, the former tenant. A declaration from the applicant alone is admissible and can succeed, but a council is far less likely to test a case supported from several directions.

Write them properly. Each declaration should state who the declarant is, how they know the property, the period they can speak to, and what they personally observed, in dates. Exhibit any documents they hold and refer to them by number. Keep out opinions about planning law.

Utility bills, tenancy agreements and photographs

Presentation changes outcomes. A box of unsorted paperwork invites doubt, an indexed bundle invites agreement.

Build a chronology first: a single table with one row per year, showing what evidence covers that year and what it shows. Then order the appendices to match. An officer who can see at a glance that every year from 2013 to 2026 is covered by at least two independent sources will approach the case very differently from one who has to construct that table themselves.

Where the evidence is thin for particular years, say so in the covering Planning Statement and explain why, rather than leaving the gap to be discovered.

Where these applications go wrong

The recurring failures are worth naming.

Relying on a single unsupported declaration. Describing the use loosely, so that the certificate would not cover what the applicant actually does. Confusing the start of the works with the start of the use. Assuming that a period of vacancy does not matter. And applying for a certificate where the use has changed in character during the period, so that the thing that has been happening for ten years is not the thing being applied for.

There is also a category of case that should not be brought at all. Where a breach was deliberately concealed, the legislation allows a council to seek a planning enforcement order, and the time limits can be extended. An application that draws attention to a concealed breach can prompt exactly the action the applicant was trying to avoid. Take advice before applying in those circumstances.

Assembling the evidence bundle

A workable structure, in order:

1. A covering statement setting out the use claimed, the period, the legal basis for immunity and a summary of the evidence.
2. The chronology table.
3. Statutory declarations, numbered.
4. Documentary appendices in date order, cross-referenced to the chronology.
5. Plans identifying the land and, where relevant, the extent of the use within a building.
6. The application form and fee.

An illustrative example: an application for a certificate for use of a terraced house as a six-person HMO might carry the council's own licensing history from 2016, twelve tenancy agreements spanning 2015 to 2026, deposit protection records, council tax correspondence, and declarations from the managing agent and two long-standing neighbours. Where parking is likely to be raised by objectors, a short parking survey is worth having for the separate planning conversation, though it has no bearing on the certificate itself.

Pay attention to the fee. For an existing use certificate it is normally calculated as though a planning application were being made for that use, so check the current national fee schedule before submitting.

Enter your postcode on PlanScope to see which supporting documents a change of use or HMO scheme is likely to need.

This is general guidance, not legal advice. Check the position with your local planning authority or a qualified professional before relying on it. A lawful development certificate is the only formal way to confirm that a use or works are lawful. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.