Prior notification or prior approval: the difference

Prior notification vs prior approval is a real distinction with real deadlines attached. A prior notification under Part 6 of the GPDO 2015 asks the council one narrow question: does it want to approve the siting, design and external appearance of the building? A prior approval application asks the council to approve specified matters that the Order has already listed, and it runs on a longer clock. Use the wrong form and you lose weeks, or you start work without a permission you thought you had.

The two procedures sit inside the same Order

Both routes live in the Town and Country Planning (General Permitted Development) (England) Order 2015. Both are permitted development, which means the right to build comes from the Order rather than from a grant of planning permission. Neither is a planning application in the ordinary sense, and in neither case is the council weighing up the whole proposal against the development plan.

What differs is the question put to the authority. Under Part 6 you notify, and the council decides whether it wants a say. Under the prior approval classes you apply, and the council must decide whether to approve the matters the Order specifies.

The practical consequence is in the timetable, the fee and the enforcement risk if you move too early.

What a Part 6 agricultural notification asks for

Part 6 covers agricultural and forestry development. Class A applies to agricultural units of 5 hectares or more, Class B to units between 0.4 and 5 hectares, with different limits on each. Larger buildings, new private ways and certain excavations trigger the notification duty.

The application is for a determination as to whether the prior approval of the authority will be required for the siting, design and external appearance of a building, or for the siting and means of construction of a private way. That wording matters. The council cannot use Part 6 to reopen whether the building is reasonably necessary for agriculture, although it can and will test that the development falls within the class at all.

Submit a written description of the proposed development, the materials to be used and a plan showing the site. Then wait. If the council tells you prior approval is not required, you can build in accordance with the details submitted. If it tells you approval is required, you cannot start until you have it.

What a prior approval application asks for

The prior approval classes work the other way round. The Order states which matters the council may consider, and you must apply for approval of those matters before you begin.

Class MA in Part 3 is the one most readers meet: commercial, business and service use to dwellinghouses. Class Q covers agricultural buildings to dwellings. Part 20 covers new dwellings on top of existing buildings. Each lists its own matters, from transport and highways impacts to flooding, contamination, noise and the external appearance of the building.

Paragraph W of Part 3 is the procedural engine behind those classes. It sets the information to be supplied, the consultation the authority must carry out, the 56 day period and the deemed grant. Read it alongside the class itself rather than on its own, because the class can add requirements.

Determination periods and what silence means

This is where money is won and lost.

Under Part 6, development must not begin before the expiry of 28 days from the date the council received the notification, unless the council has told you in writing that prior approval is not required. Silence for 28 days is permission to proceed in accordance with the details you submitted. Submit vague details and you have a vague right.

Under paragraph W, if the authority does not give you notice of its decision within 56 days beginning with the day the valid application was received, the development is taken to be approved. The deemed grant is genuine, and it is used in practice. It is also fragile, because it depends on the application having been valid on the day it was received. An application missing a required document or the correct fee was never valid, so the 56 days never started.

Keep the proof. Date stamped submission receipt, the fee payment reference, a copy of everything sent. If you are relying on a deemed grant two years later when a buyer's solicitor asks, that file is the whole of your case. The safest confirmation is a lawful development certificate under section 192 of the Town and Country Planning Act 1990, which is the only formal way to establish that works are lawful.

Fees, forms and the drawings people skimp on

Both routes use Planning Portal forms, and both carry a fee set by the national fee regulations. Those fees have been indexed annually since April 2025, so check the current schedule rather than a figure quoted in an old article.

What is submitted differs sharply:

1. For a Part 6 notification, a description of the development, the materials, and a plan showing the site. Short, but the description binds you.
2. For a prior approval application, the specific reports the class names. Class MA expects information on transport and highways, contamination, flooding, noise from commercial premises and natural light to all habitable rooms.
3. For Part 20, structural information and external appearance material that goes well beyond a site plan.

The common error on prior approval is treating the Order's list of matters as a menu. It is the scope of the council's consideration, so every matter listed needs something in the pack addressing it. A planning statement that walks through each matter in the order the class sets them out avoids most invalidity letters.

Starting work before the clock runs out

Begin development early and you are not building under permitted development. You are building without permission.

The right in the Order is conditional on the procedure being followed. Break the condition and the whole of the development is unauthorised, which opens the council to enforcement action and leaves you applying retrospectively with none of the protection the Order gave you. For an agricultural building that is an expensive mistake, because the fallback is a full application where the council can consider landscape impact, access and whether the building is needed at all.

If the deadline is close and the council has not responded, the discipline is to wait out the day and keep the evidence, rather than to take a view in the yard.

Choosing the route for a farm building

Start by asking whether the unit meets the area threshold for Class A or Class B, then whether the building sits inside the dimensional limits of the class, then whether the site is within an excluded area such as a National Landscape or the curtilage of a listed building. Only then does the notification question arise. Many proposals fail at the first or second step and need a full application, and finding that out before the fee is paid saves a cycle.

Where the proposal is a conversion rather than a new building, Class Q and its prior approval route applies instead, with a very different information requirement. The two are often confused because both involve agricultural buildings. They are different classes with different tests, much as an ancillary use and a material change of use are different questions about the same barn.

Checking which supporting documents a given class expects is the part people underestimate. The full list of report types shows what a transport, contamination or noise matter usually needs behind it, and the planning law timeline is where to follow changes to the Order itself.

This is general guidance, not legal advice; check the position with your local planning authority or a qualified professional before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.

Enter your postcode on PlanScope to see which reports a Part 6 or prior approval submission on your land is likely to need.