S106 §1:100 · cil split

CIL versus Section 106

Reviewed by Chartered Planner (MRTPI) and Chartered Surveyor (MRICS) · 2026-06-21
Direct answer · 51 words
Once an LPA adopts CIL, infrastructure that is funded via CIL cannot also be sought via S106. The reg 122 necessity test governs which obligations are permissible. The reg 123 list was repealed in 2019, replaced by Infrastructure Funding Statements. CIL relief (charity, social housing, self-build) sits alongside but does not displace S106.

The post-2019 split

The CIL (Amendment) (No.2) Regs 2019 [CIL (Amendment) (No.2) Regs 2019]repealed reg 123 (the list of infrastructure that could be funded only through CIL) and required LPAs to publish Infrastructure Funding Statements instead. In practice CIL funds general infrastructure (general transport, general education capacity); S106 funds site-specific or directly-related mitigation.

Reg 122 necessity test

CIL Regs 2010 reg 122 [CIL Regs 2010 reg 122] governs every S106 head. The three-limb test: necessary to make development acceptable in planning terms, directly related to the development, and fairly and reasonably related in scale and kind. An obligation that fails any limb cannot be sought.

CIL charging schedule

Each charging authority publishes a charging schedule with rates per sqm GIA by use class. Rates vary by zone and by use class. The combined-load calculator at /cil-vs-s106/combined-load-calculator lets the buyer input the CIL rate alongside the S106 estimate.

CIL relief

Relief reduces or eliminates the CIL liability but does not substitute for an S106 obligation. The reg 122 test applies independently.

S106 §1:50 · related

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