CIL liability: who pays, when and on what
The levy follows the land, not the paperwork. Here is how liability is assumed, how the chargeable amount is calculated, and why the commencement notice decides the bill.
Community Infrastructure Levy liability attaches to the development, follows the land and does not care who signs the forms. If nobody assumes liability before work starts, the charge lands on the owner of the land, along with any surcharges the collecting authority adds. For a self-builder putting up one or two houses, that is the difference between a manageable payment plan and a demand for the whole sum within 60 days.
The levy is fixed by a published charging schedule. There is no negotiation, no viability argument at the point of payment and no discretion in the arithmetic.
Which developments are chargeable
A chargeable development is one that creates 100 m2 or more of new gross internal floorspace, or creates one or more new dwellings of any size. A 60 m2 annexe forming a separate dwelling is chargeable. A 90 m2 extension to an existing house, on its own, is not, though the residential extension exemption exists precisely because the threshold catches combinations.
Buildings into which people do not normally go, or go only intermittently to inspect or maintain plant, are outside the charge. So are structures that are not buildings.
Whether your council charges at all is a separate question. The levy is optional for charging authorities, and rates differ by zone, by use and sometimes by unit size within a single district. Find the adopted charging schedule on the council's own website before you assume a rate.
Assumption of liability and the forms
The sequence is administrative and unforgiving. It runs like this:
- Submit the CIL Additional Information form with the planning application, so the collecting authority can calculate the charge.
- Assume liability using the assumption of liability form, ideally at the same time as the application and certainly before starting work.
- Receive the Liability Notice, which sets out the chargeable amount and how it was calculated. Check it line by line.
- Claim any relief or exemption you are entitled to, and receive the decision, before development starts.
- Submit the Commencement Notice, naming the intended start date, before that date arrives.
- Receive the Demand Notice, which sets the payment dates.
Liability can be transferred or withdrawn later, but only within the rules, and only before the final payment falls due. Where a plot is sold between permission and start on site, deal with the transfer expressly in the contract rather than assuming it moves with the title.
How the charge is calculated
The chargeable amount is the levy rate for the zone, multiplied by the net chargeable area, adjusted by an index published annually so that rates keep pace with build costs.
Net chargeable area is the point where money is won or lost. Existing floorspace can be deducted where the building has been in lawful use for a continuous period of at least six months within the three years before permission was granted. Miss that window and a building you are demolishing counts for nothing, so the levy is charged on the full gross internal area of the new scheme rather than the difference.
That six-month rule catches barn conversions, long-empty offices and houses bought vacant. If you are buying a site with a redundant building, evidence of lawful use, such as utility bills, business rates records or tenancy agreements, is worth gathering before completion rather than after.
Measure gross internal area properly. It includes internal walls, circulation, plant rooms and integral garages, and disputes over a few square metres are common where a designer has used net internal area out of habit.
Illustrative example. A self-builder buys a plot with a 70 m2 garage block that has stood empty since it was last used commercially four years ago, and proposes a single 140 m2 house. Because the garage has not been in lawful use for six months of the previous three years, none of its floorspace is deducted, and the levy is charged on the full 140 m2 rather than on 70 m2. The figures here are illustrative only, and the rate that applies depends on the adopted charging schedule for that district.
The commencement notice and why timing decides everything
Development is treated as starting on the day a material operation begins, which includes digging a trench for foundations, laying out a road and demolition where it forms part of the development. Site clearance and archaeological trial trenching usually do not count, but the line is fine enough to be worth checking.
Submitting the Commencement Notice before that day is the single most valuable piece of admin in the whole process. Without it, the collecting authority can treat the full amount as payable immediately, any instalment policy falls away, and self-build or residential annexe relief already granted can be withdrawn entirely. People have lost five-figure exemptions to a missed form.
Send it, get an acknowledgement, and keep the acknowledgement.
Instalments, demand notices and disputes
Once commencement is notified, the collecting authority issues a Demand Notice with the amount and the payment dates. If the authority has adopted an instalment policy, payments are staged according to that policy, which is published and applies to everyone equally. Where there is no instalment policy, the whole amount is due within 60 days of commencement.
There are formal routes to challenge the arithmetic. A request for review of the chargeable amount goes to the collecting authority within 28 days of the Liability Notice, and an appeal against the reviewed amount goes to the Valuation Office Agency. Separate appeals exist against surcharges, against a deemed commencement date and against the apportionment of liability between owners. All of them are time-limited and most require you to have raised the point at the earlier stage.
Surcharges and what triggers them
Part 9 of the CIL Regulations 2010 sets out the surcharges. The pattern is worth knowing even if you check the current figures before relying on them.
| Failure | Surcharge |
|---|---|
| No assumption of liability before commencement | A flat sum per liable owner |
| Failure to submit a commencement notice | A percentage of the chargeable amount, subject to a cash cap |
| Late payment | A percentage of the outstanding amount, applied again at set intervals |
| Failure to respond to an information notice | A flat sum |
Beyond surcharges, the authority can serve a stop notice on the development, take enforcement action, register a charge on the land and in extreme cases pursue committal. Interest runs on unpaid amounts.
None of this is discretionary in the way a section 106 negotiation is. Once the schedule is adopted and the permission is granted, the levy is arithmetic.
Budget for it at appraisal stage rather than at commencement. On a small scheme, the levy sits alongside the technical evidence base as one of the two costs that most often derail a first-time developer, so it belongs in the same spreadsheet as your consultant fees. Where you are still working out which supporting documents the application itself will need, the report index sets out what a typical minor residential scheme attracts, and PlanScope pricing shows what drafting those documents costs. If you want a scheme-specific starting point, enter the site postcode and work through the guided questions.
For sites where viability is tight, remember that the levy is charged whether or not the scheme makes money, and that affordable housing delivered through a planning obligation is a separate cost sitting on top of it.
This is general guidance, not legal advice. Levy rates, forms and surcharge amounts change, so check the position with your collecting 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.
Frequently asked questions
What size of development triggers the levy?
A chargeable development is one creating 100 m2 or more of new gross internal floorspace, or creating one or more new dwellings of any size. A small annexe forming a separate dwelling is therefore chargeable even though it is well under 100 m2. Buildings people do not normally enter, such as some plant enclosures, fall outside the charge.
What happens if nobody assumes liability?
Liability defaults to the owners of the land, apportioned between them, and a surcharge applies. Assuming liability is a simple form and costs nothing, so submit it with the planning application. Liability can be transferred later within the rules, but only before the final payment falls due, which matters when a plot changes hands mid-project.
Can I deduct the floorspace of a building I am demolishing?
Only if the building has been in lawful use for a continuous period of at least six months within the three years before permission was granted. A long-empty barn or office usually fails that test, and the levy is then charged on the full floorspace of the new scheme. Gather evidence of lawful use before you buy the site.
What does a missed commencement notice cost?
The collecting authority can treat the whole chargeable amount as immediately payable, withdraw any instalment arrangement, and add a surcharge. Self-build and residential annexe relief already granted can be lost entirely. Submit the notice before the first material operation on site, and keep the acknowledgement with your project records.
Can I challenge the amount charged?
Yes. Ask the collecting authority to review the chargeable amount within 28 days of the Liability Notice, then appeal the reviewed figure to the Valuation Office Agency. There are separate appeals against surcharges, against a deemed commencement date and against apportionment between owners. Each has its own deadline and most require the earlier step to have been taken.
Sources and further reading
This article is general guidance about the planning system in England and, where stated, the rest of the UK. It is not legal or professional advice. Check your local planning authority’s validation requirements and take professional advice for your specific site.