The RICS Community Infrastructure Levy Index for 2026 is 400. It applies from 1 January 2026 and is used to update rates contained in local CIL charging schedules.
The figure is not a national CIL rate. A council may have several rates for different uses and charging zones, and each rate must be considered alongside the applicable index figures, net chargeable floorspace and planning permission history.
This guide explains the 2026 index, the standard calculation, the June 2026 clarification for outline permissions and the checks applicants should make before relying on an estimated CIL figure.
Quick answer
The RICS Community Infrastructure Levy Index for 2026 is 400 and applies from 1 January 2026. It is used to update rates contained in local charging schedules. The final CIL charge still depends on the council’s adopted rate, the development type, chargeable floorspace, the relevant index figures and the planning permission history.
CIL indexation 2026 at a glance
| Item | 2026 position | Why it matters |
| RICS CIL Index | 400 | Used for the 2026 calendar year. |
| 2025 index | 391 | The 2026 figure represents a 2.3% annual increase. |
| Effective date | 1 January 2026 | Relevant to charges calculated for the 2026 calendar year. |
| Standard formula | R x A x Ip / Ic | Combines the local rate, area and two index years. |
| Outline permission guidance | Clarified on 17 June 2026 | Ip is linked to the year the outline permission was granted. |
What is CIL indexation?
CIL charging schedules can remain in force for many years. Indexation adjusts the rates so that the levy responds to changes in construction prices rather than remaining fixed at the amount adopted in an older schedule.
From 1 January 2020, the annual figure used for current calculations is the RICS CIL Index prepared and published by the Building Cost Information Service. The figure for each calendar year is published in the preceding autumn and applies from 1 January.
The 2026 index is 400. The 2025 index was 391, so the annual movement is approximately 2.3 per cent.
The CIL calculation formula
For a standard case, the amount chargeable at a given rate is calculated using:
R x A x Ip / Ic
The terms mean:
- R: the relevant rate in the charging schedule, expressed in pounds per square metre
- A: the deemed net area chargeable at that rate
- Ip: the index figure for the calendar year in which planning permission was granted
- Ic: the index figure for the calendar year in which the charging schedule containing rate R took effect
A project with different uses or areas charged at different rates may require separate calculations that are then added together. Reliefs and exemptions are considered separately from the underlying chargeable amount.
A simple 2026 worked example
Assume a council introduced a residential rate of £150 per square metre in 2025. The index for 2025 was 391. Planning permission is granted in 2026, when the index is 400.
| Input | Amount |
| Charging schedule rate, R | £150 per square metre |
| Net chargeable area, A | 120 square metres |
| Permission-year index, Ip | 400 |
| Schedule-year index, Ic | 391 |
£150 x 120 x 400 / 391 = £18,414.32
The simplified indexed rate is approximately £153.45 per square metre. The example assumes one rate, no relief, no existing floorspace deduction and no special permission history. It should not be used as a project quotation.
Why the charging schedule headline rate may be different
An adopted schedule records the base rate approved by the authority. The amount shown on a Liability Notice may differ because of:
- annual indexation
- the year in which the schedule took effect
- the year planning permission was granted
- different rates for uses or charging zones
- netting off qualifying existing floorspace
- phasing or an amended permission
- relief or exemption applied after the chargeable amount is calculated
Use the adopted charging schedule to identify the correct base rate, then check the authority’s current annual rate summary and the permission history.
Which index year applies to a full planning permission?
For a standard full planning permission, Ip is the index for the calendar year in which planning permission was granted. Ic is the index for the year in which the relevant charging schedule came into effect.
A permission granted in December 2025 and a permission granted in January 2026 can therefore produce different indexed rates, even where the development and base charging schedule rate are identical.
What changed for outline planning permissions in June 2026?
Government guidance was updated on 17 June 2026 to clarify the treatment of outline permissions.
For the indexation formula, Ip is the index for the year in which the outline planning permission was granted. It is not replaced by the year in which the last reserved matters are approved, and it does not change because the permission is phased.
This point matters because an outline permission can remain live for several years. Applying the reserved-matters year as Ip could materially alter the calculation.
What if a revised charging schedule starts before reserved matters are approved?
The same government guidance confirms that where outline permission was granted while an earlier charging schedule was in force, and a revised schedule comes into effect before reserved matters are approved, the earlier schedule should be used when the chargeable amount is calculated after reserved matters approval.
The dates to retain in the project record are therefore:
- the date the outline permission was granted
- the charging schedule in force on that date
- the date and scope of each reserved matters approval
- the index figure for the outline permission year
- the index figure for the year the relevant schedule took effect
How does indexation work for phased permissions?
Each phase of a phased planning permission is treated as a separate chargeable development. The calculation may therefore need to be carried out phase by phase, using the permission and schedule rules applicable to that phase.
The June 2026 clarification confirms that the Ip figure for an outline permission is still tied to the outline permission year, even where the permission is phased. Other elements of the calculation, including floorspace and rates, still need to be established for each chargeable phase.
How does a section 73 permission affect indexation?
A section 73 permission can change the CIL position where it amends a condition attached to an earlier permission. The regulations use notional calculations to compare the amended permission with the permission it changes.
Government guidance explains the broad treatment:
- where liability is unchanged, the authority should reissue the Liability Notice
- where the amendment increases liability, the additional element is calculated using the latest relevant index
- where the amendment reduces liability, the reduction is calculated using the original indexed rate
Section 73 calculations can be more complex for outline, phased or pre-CIL permissions. The planning permission chain should be reviewed before accepting a revised figure.
How existing floorspace affects the indexed amount
Indexation changes the rate, but the final charge also depends on the net chargeable area.
Certain existing floorspace may be deducted where the statutory tests are met. In broad terms, an existing building may need to have been in lawful use for a continuous period of at least six months within the three years ending on the day planning permission first permits the chargeable development.
Where the authority does not have sufficient reliable information about the area or lawful use of a building, it may treat the relevant gross internal area as zero. Evidence should therefore be assembled before the Liability Notice is issued, rather than after commencement.
Common CIL indexation mistakes
1. Using the original charging schedule rate without applying indexation.
2. Treating the annual index figure as the council’s rate per square metre.
3. Using the current year for both Ip and Ic.
4. Using the reserved-matters year as Ip for an outline permission.
5. Applying a revised schedule to an outline permission governed by the earlier schedule.
6. Ignoring different rates for separate uses or charging zones.
7. Calculating against gross proposed floorspace without checking qualifying existing floorspace.
8. Using an online estimate after the permission has been amended without checking the section 73 rules.
CIL indexation checklist for planning professionals
1. Identify the charging authority and collecting authority.
2. Download the adopted charging schedule and maps.
3. Confirm the date the relevant schedule took effect.
4. Record the permission type and grant date.
5. For outline permissions, retain the original outline decision and use the outline permission year for Ip.
6. Check the 2026 annual rate summary and the RICS CIL Index.
7. Separate areas charged at different rates.
8. Verify gross internal area and any existing floorspace evidence.
9. Review amended or phased permission rules before finalising the estimate.
10. Compare the council’s Liability Notice with the project record before commencement.
Does the 2026 index apply in Wales?
This article is written around the current England guidance and the June 2026 clarification for outline permissions. CIL also operates in parts of Wales, but applicants should verify the applicable Welsh regulations, form versions and local authority calculation documents before using the England workflow.
The safest approach is to use the charging authority’s own current calculation material and request clarification where an older Welsh schedule or permission history creates uncertainty.
How UK Planning Gateway supports CIL preparation
UK Planning Gateway helps planning professionals structure planning application information and supporting documents against published Local Planning Authority requirements. Consistent floorspace information across drawings, application forms and CIL submissions reduces avoidable calculation queries.
The authority remains responsible for the statutory calculation and Liability Notice. UK Planning Gateway does not provide a binding CIL valuation or determine liability.
Frequently asked questions
What is the CIL Index for 2026?
The RICS CIL Index for the 2026 calendar year is 400. It was published by BCIS in October 2025 and applies from 1 January 2026.
Is 400 the CIL rate per square metre?
No. It is an index figure used in the statutory formula. The base rate per square metre comes from the relevant council charging schedule.
How much did the CIL Index rise in 2026?
The index increased from 391 in 2025 to 400 in 2026, a rise of approximately 2.3 per cent.
Which year is used for an outline permission?
Government guidance states that Ip is the index for the year in which the outline permission was granted, regardless of when the last reserved matters are approved or whether the permission is phased.
Can I calculate CIL from the charging schedule alone?
The schedule identifies the base rate, but a project calculation also requires the relevant index years, net chargeable area, charging zone, development use and permission history.
Check the indexed rate before relying on a CIL estimate
A rate copied from an old schedule can understate or overstate the likely charge. Check the schedule year, permission year, current index, development use, charging zone and net floorspace before giving the figure to a client or including it in an appraisal.
Check your council’s CIL documents
Find the charging schedule, maps and current annual rate information.
Check your council’s CIL documents
See the latest guidance updates, reforms and council changes.
Important information
This article provides general information based on published government, legislation and local authority material. It does not constitute legal, financial, valuation or professional planning advice. CIL liability depends on the planning permission, development history, applicable regulations, dates and decisions of the relevant charging or collecting authority. Check the authority’s current documents before submission or commencement.