RICS CIL Index 2026 Announcement

The Building Cost Information Service (BCIS) has today, Monday 27 October 2025, released the Royal Institution of Chartered Surveyors (RICS) Community Infrastructure Levy (CIL) Indexation factor for 2026 – set at 400 – which takes effect from 01 January 2026.

Indexation is used to account for inflationary changes in industry costs, in this case construction, to align the CIL base rates set by the individual Local Planning Authority (LPA) to current market levels; and for projects within Greater London, Mayoral CIL also.

Previously, the CIL Regulations 2010 (as amended) had been using the BCIS All-in Tender Price Index (TPI), a common method for cost planning in the construction industry. However, with the 2019 amendments to the CIL Regulations, the CIL Index was set up to fix the indexation for the following year, as the TPI’s active database would fluctuate to account for a more precise position with the introduction of new project information – usually until around 12-18 months until it was fixed.

The CIL Index is published on the same base as the BCIS TPI – still used for dates preceding the introduction of the CIL Index – and is calculated by reference to the average of the BCIS TPI over the four quarters prior to the fourth quarter each year.

Todd Arnison, Senior Property Tax Surveyor and part of E³ Consulting’s CIL team says “The index initially declined in its early years of operation, from 2020, – owing to the economic impact caused by the Covid pandemic. However, since then the affects of the wider global inflation have taken hold with the CIL Index rising to 391 in 2025 and now 400 in 2026 – this equates to roughly a 2.3% year-on-year rise. This means that new planning permissions granted from 01 January 2026 will see higher CIL liabilities, subject to LPA adoption and respective rates for planning use. We suspect that most planning permissions applied for from now until the end of the year will be subject to the higher CIL index rate, owing to planning permissions being granted outside of the usual 8-12 week timeline.”

Please do get into contact with the E³ Consulting team to understand what this change in the CIL Index for 2026 could mean for you and your new projects. We regularly review and challenge CIL liabilities on behalf of our clients, including formulating mitigation strategies.

We are happy to set out how we may be able to assist through our free HEALTHCHECK on hello@e3consulting.co.uk or 0345 230 6450.