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Free 2026 London Planning Report — How much do CIL forms cost in London?

London high street lined with Victorian shopfront parades and flats above, the kind of building where a conversion or new home can bring a levy

CIL Form PreparationFrom £49

How much do CIL forms cost in London?

Community Infrastructure Levy forms for a London project cost our fixed £49, with no VAT charged. We check whether the project is liable, whether you qualify for the exemption for a residential extension or annex, complete the forms from your permission and drawings, and give you a dated checklist, because the levy punishes late paperwork far more than the forms cost.

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The short answer: a small fee that guards a large one

Our CIL forms cost £49. We check whether your project is liable for the levy at all, and whether you qualify for the exemption for a residential extension or annex. We complete the forms from your planning permission and drawings, with a dated checklist of what must be sent before work begins and notes on how to send them.

A reminder comes with it of what to do if the start date moves, which is the part people forget. The forms are ready for you to send to the council; the council is the collecting authority and takes the notices and claims.

The CIL paperwork in order
  1. Check liability

    Is the project liable for the levy at all, and does the extension exemption apply?

  2. Claim the exemption

    Where it applies, the claim must reach the council before work starts.

  3. Assume liability

    Where the levy is due, someone must assume liability to pay it.

  4. Send the commencement notice

    The notice goes in no later than the day before work begins.

Who is liable at all

Government guidance says the levy may apply where the gross internal area of new build is 100 square metres or more, though that limit does not apply to new houses or flats, which can be liable at any size. Householder extensions that enlarge the main home without creating a separate dwelling are exempt, and extensions under 100 square metres that do not create a new dwelling are also exempt under the minor development exemption.

That is the headline, and councils set their own charging schedules. So a rear extension on your own home is usually not charged and a new house is. We check the case against the council's own charging position before we tell you.

The exemption has conditions, and a clock

The exemption for an annex or extension needs the owner to own a material interest in a dwelling, and to occupy the main dwelling as their sole or main residence, with the development a residential annex or a residential extension. A landlord's extension to a let property is therefore a different case.

Then the clock. The claim must be received by the council before commencement of the chargeable development, and it lapses if the development starts before the council has notified its decision on the claim. A builder who turns up early has cost you the exemption.

Rear extension under construction with blockwork walls and a steel beam opening up the back of a house
Once the first spade goes in, the exemption claim can no longer be made in time.

The notices and the penalties

A commencement notice must be submitted to the council no later than the day before the day on which the chargeable development is to be commenced. If development starts before a valid notice is received, the council may impose a surcharge equal to 20 per cent of the chargeable amount or £2,500, whichever is the lower amount (regulation 83).

Where nobody has assumed liability and the development has commenced, the council may impose a surcharge of £50 on each person liable (regulation 80). The surcharge is capped by that lower amount, and a lost exemption is the larger risk.

How it connects to the rest of the project

The forms follow planning permission and come before work begins, so the CIL paperwork is the last thing before the builder starts. The post on what a tender package costs explains the step before it. If work has already started without the paperwork, our post on retrospective permission covers the planning side.

Our CIL form preparation page shows the service. If your project is a new house, our post on new build costs shows the other items alongside the levy.

Sources

Every figure in this article, where it comes from and a link to the original.

  1. the gross internal area of new build is 100 square metres or more: PPG Community Infrastructure Levy, para 003: (source wording: "the gross internal area of new build is 100 square metres or more"); the limit does not apply to new houses or flats. www.gov.uk
  2. the main dwelling as their sole or main residence: CIL Regulations 2010 reg 42A(1)(b)-(c): exempt where P (source wording: "occupies the main dwelling as P's sole or main residence") and the development is a residential annex or a residential extension. www.legislation.gov.uk
  3. before commencement of the chargeable development: CIL Regulations 2010 reg 42B(2)(a): the claim must (source wording: "be received by the collecting authority before commencement of the chargeable development"). www.legislation.gov.uk
  4. lapses if the development starts before the council has notified its decision on the claim: CIL Regulations 2010 reg 42B(3): (source wording: "a claim under this regulation will lapse where the chargeable development to which it relates is commenced before the collecting authority has notified the claimant of its decision on the claim"). www.legislation.gov.uk
  5. no later than the day before: CIL Regulations 2010 reg 67(1): (source wording: "a commencement notice must be submitted to the collecting authority no later than the day before"). www.legislation.gov.uk
  6. £2,500: CIL Regulations 2010 reg 83(1): (source wording: "a surcharge equal to 20 per cent of the chargeable amount payable in respect of D" or "£2500, whichever is the lower amount"). www.legislation.gov.uk
  7. £50: CIL Regulations 2010 reg 80: (source wording: "A collecting authority may impose a surcharge of £50 on each person liable to pay CIL" where nobody has assumed liability and development has commenced). www.legislation.gov.uk

Questions people ask

Do you send the forms to the council?
We complete them and tell you how to send them. You send them, so the dates are yours to control.
Do I pay VAT on your fee?
No. The fee shown is the total you pay; no VAT is charged.
Is my extension liable?
Householder extensions to your own main home are generally exempt if you claim in time. We check yours.
What if the start date moves?
Tell us. The notice and claim dates depend on it, and we say what to resend.
Does the levy apply everywhere?
Only where the council has a charging schedule. We tell you what applies to your address.

Photographs: John Cameron (Unsplash License); Brett Jordan (Pexels License).

CIL Form Preparation: a fixed fee from £49

Read more on the cil form preparation service page, or send your address below and we reply within one working day.

CIL Form Preparation

from £49

Every price is the full fixed fee you pay. No VAT is charged. Council application fees are paid to the council separately.

What you get

  • A check of whether your project is liable for the levy at all
  • Whether you qualify for the exemption for a residential extension or annex
  • The forms completed from your planning permission and drawings
  • A dated checklist of what must be sent before work begins
  • A reminder of what to do if the start date moves

Get your fixed-fee quote

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