An agreement includes the council as a party; a unilateral undertaking is given by a person with an interest in the land and cannot bind a council which is not a party to it. The obligations run with the land. [1]
Why an obligation may be needed
A planning obligation must be necessary to make the development acceptable, directly related to it, and fairly and reasonably related in scale and kind. Those statutory tests apply whether or not the authority also charges CIL. An obligation is not simply an extra payment the council may request without explaining its relationship to the development. [1]
The NPPF published on 17 August 2026 uses the current policy code DM6 for planning conditions and obligations. It says obligations should be used where unacceptable impacts cannot be addressed through a planning condition. It also says conditions should not require payments of money. [2][3]
For example, Epping Forest secures relevant Special Area of Conservation mitigation payments through its Section 106 process. Its website provides different templates for SAC-only cases and cases involving broader planning obligations. [4]
Agreement or unilateral undertaking?
The choice depends on what must be secured and which parties need to give enforceable promises. A unilateral undertaking can be suitable for a defined owner obligation, but it cannot create a reciprocal council obligation by simply writing one into a document the council does not execute. [1]
Use the authority's current requirements as the starting point. Epping Forest's 2026 undertaking guidance asks for the property and planning details, title information and the relevant parties. Where land is mortgaged, the lender's interest also needs to be addressed. Do not assume the planning applicant is the only person whose signature matters. [5]
What to check before signing
Have the legal adviser explain the precise obligation, the payment calculation, any indexation, the event triggering payment, notification requirements and any restrictions on commencement or occupation. Review the definitions: a commitment linked to the start of development may affect the build programme differently from one linked to occupation. The government's draft standard agreements illustrate why these are separate provisions requiring careful drafting. [6]
Keep legal and administrative costs distinct from the contribution itself. Epping Forest requires an undertaking for its reasonable legal costs and explains that additional work on amended documentation may increase those costs. That local requirement should not be mistaken for a fixed national Section 106 fee. [4]
Do not merge it with CIL
CIL and Section 106 can both apply. National guidance allows funding from different routes to support infrastructure, subject to the applicable tests and reporting. It does not establish a rule that paying CIL automatically removes all site-specific obligations. [1]
Maintain a schedule showing each obligation, its purpose, amount or formula, trigger and evidence of discharge. This makes it easier to distinguish an unpaid contribution from a drawing condition that still needs approval.
Proposed standard documents
MHCLG's consultation on standard planning agreements for medium-sized sites runs from 25 August to 20 October 2026. It includes draft bilateral and unilateral documents and affordable-housing schedules. These are consultation drafts rather than final mandatory templates for every small project. [6]
A solicitor should check the deed and the site's ownership before it is executed; a generic template does not resolve project-specific liabilities.