Deed of Variation: How to Modify a Section 106 Agreement

A signed Section 106 agreement isn't immutable. Schemes change. Market conditions shift. Trigger points get re-engineered. There are two distinct routes to modifying an S106 once it's in place — a contractual deed of variation, available at any time with all parties' agreement, and a statutory application under Section 106A of the Town and Country Planning Act 1990, available after five years.

This guide explains both routes, when each applies, and what a developer or planning consultant needs to prepare for.

This covers England only. This is general guidance, not legal advice. Always seek legal advice before initiating modification of a signed planning obligation.

Why a Section 106 Might Need Modification

Common triggers include:

• Phasing changes. The original agreement tied an obligation to "occupation of the 50th dwelling" but the developer has restructured the scheme into smaller phases.
• Tenure mix changes. The registered provider partner has withdrawn and the new partner requires a different tenure split.
• Trigger timing. Cash-flow pressure on the developer means a financial contribution due at commencement needs deferral.
• Specification changes. Highway works specified in the agreement no longer match the highway authority's current adopted standards.
• Discharge of obsolete obligations. A pre-2018 affordable housing obligation that's no longer policy-compliant after a Local Plan update.
• Spend-by deadline extensions. Where a council faces a clawback deadline and the planned project has been delayed.

Modification doesn't undo the obligation — it changes the terms. The agreement remains binding in its modified form.

Route 1: Contractual Deed of Variation

The simplest route — and the one used in most modification cases — is a deed of variation: a new contract between the original parties (or their successors in title) that varies specific terms of the original S106. It works because the S106 is a deed of contract, and contracts can be varied by agreement of the parties.

When It Applies

A deed of variation can be executed at any time after the original agreement is signed. There's no statutory waiting period. The only constraint is that all bound parties must agree — the developer, any successors in title to the site, the local planning authority, and any other named party (e.g. registered providers, highway authorities, the GLA in London).

If any bound party objects, the deed-of-variation route fails and the developer's only remaining option is the statutory route below (if five years have elapsed).

Process

1. Initiate the request. The developer or current landowner approaches the LPA in writing with the proposed variation and the reasons for it. Most LPAs publish a Section 106 modification application process — typically with a fee.
2. Officer assessment. The LPA's planning officer assesses whether the proposed variation is acceptable in policy terms. Modifications that weaken the obligation package face higher scrutiny.
3. Consultation. Depending on the variation, consultation with statutory consultees (e.g. highways authority) and sometimes public consultation may apply.
4. Decision. A delegated officer decision for minor variations; committee report for material changes. Some councils' constitutions require committee for any S106 modification.
5. Drafting. Once approval is granted, the LPA's legal team drafts the deed of variation. Costs are typically passed to the developer.
6. Execution. All parties sign the deed. It's registered against the title at the Land Registry to bind successors.

Timing

A simple deed of variation can complete in 6-12 weeks. More complex variations involving committee approval or external consultees can take 4-6 months.

Fees

LPA fees vary widely — typically a fixed application fee plus the council's legal drafting costs. Developers should budget several thousand pounds for legal and administrative costs even on simple variations.

Route 2: Statutory Application Under Section 106A

Where the LPA refuses a deed of variation, or where the developer wants to pursue modification against the council's wishes, the statutory route under Section 106A of the Town and Country Planning Act 1990 becomes available.

The Five-Year Rule

Section 106A allows any person bound by a planning obligation to apply to the LPA for the obligation to be modified or discharged — but only after five years from the date the obligation was entered into (or such other period as may be specified in the regulations).

The five-year waiting period is the key distinction from the contractual route. It exists to prevent developers from using the statutory route to renegotiate obligations they've just signed up to. Because S106 obligations run with the land and have no fixed expiry, this five-year window often opens long before an obligation is discharged — see how long Section 106 agreements last for the full picture on durations and the deadlines that run alongside them.

Process

1. Application. The applicant (developer, landowner, or anyone bound by the obligation) submits a formal Section 106A application to the LPA. The application identifies the obligation, the proposed modification or discharge, and the grounds.
2. Determination. The LPA must determine the application within the prescribed period. The Section 106A regulations and PPG set out the procedural requirements.
3. LPA decision. The LPA can:
   • Approve the modification or discharge as applied for
   • Modify the obligation on different terms from those applied for (but only if the modified version is no more onerous than the original)
   • Refuse the application
4. Appeal. If refused or modified on terms the applicant doesn't accept, the applicant can appeal to the Secretary of State within the prescribed period.

What the LPA Considers

The statutory question is whether the obligation no longer serves a useful purpose or would continue to serve a useful purpose only if modified. This is a higher hurdle than the discretionary planning-balance test that applies to a contractual deed of variation.

In practice, applicants under Section 106A typically argue one of:

• The obligation no longer reflects policy (e.g. an affordable housing obligation that's now well above current adopted policy)
• The obligation can't be performed as originally drafted (e.g. a highway scheme that's been superseded by a different highway proposal)
• The obligation is delivering no public benefit because the underlying conditions have changed

The "no longer serves a useful purpose" test is strict. Schemes seeking modification on viability or market-conditions grounds typically struggle under Section 106A and are better routed through a contractual deed of variation if the LPA will agree.

Choosing Between the Routes

Factor	Deed of Variation	Section 106A
Timing constraint	Any time after signing	Only after 5 years
LPA discretion	Yes — LPA can refuse on planning grounds	More constrained — statutory test applies
All parties' agreement	Required	Not required (statutory process binds the LPA)
Appeal route	None — purely contractual	Yes — to Secretary of State
Typical use case	Schemes still in build-out, all parties cooperative	Older agreements, LPA disputes modification

In practice, the deed of variation route is used in the vast majority of modification cases. Developers and councils prefer the speed and flexibility of negotiated variation. Section 106A applications are the fallback for older agreements or where negotiation has broken down.

Practical Considerations for Developers

Get the Council's Position Early

Before commissioning legal drafting or technical assessments, sound out the LPA officer. A modification that the council fundamentally opposes on policy grounds will fail regardless of how well it's drafted. Officer pre-application discussions are typically informal and inexpensive.

Identify All Bound Parties

The deed of variation needs every bound party's signature. On older agreements, that can include registered providers who've transferred housing stock, highway authorities who've been reorganised, or successors in title to part of the original development site. Title checks at the Land Registry are essential before drafting.

Budget for Legal Costs

The LPA's legal drafting costs are typically recovered from the developer. On complex variations, legal costs alone can run to £10,000-£25,000 or more. Add the developer's own legal costs on top.

Document the Reasons

LPAs will scrutinise the rationale. A modification framed as "the developer changed their mind" will face harder scrutiny than one framed around concrete operational reasons — a registered provider withdrawing, a highway scheme being superseded, a phasing change driven by build-out logistics.

What This Means for Monitoring

From the council monitoring officer's perspective, a deed of variation or Section 106A modification changes the obligation record. Once executed and registered, the modified obligation is what the council tracks — not the original terms.

For schemes with multiple variations over time, the monitoring record needs to capture the variation history clearly: which obligations were modified, when, and by which deed. Without that history, future officers reviewing the file may struggle to reconcile what's actually owed against what the original agreement said.

For the developer or planning consultant, this means the variation isn't complete until it's recorded properly — on the title, in the LPA's monitoring records, and ideally with a clear audit trail of the negotiation that led to it.

Summary

Modifying a Section 106 agreement is routine in practice. Most modifications go through the contractual deed-of-variation route, which can be initiated at any time but requires all parties' agreement. Where the council won't agree, the statutory Section 106A route is available after five years — but the "no longer serves a useful purpose" test is stricter than the planning-balance test that applies to deeds of variation.

For developers and planning consultants, the deed-of-variation route is faster, cheaper, and more flexible — but only if the LPA is willing to engage. Early officer pre-application discussions are usually the best predictor of whether a modification will succeed.

Sources

• Town and Country Planning Act 1990, Section 106
• Town and Country Planning Act 1990, Section 106A
• GOV.UK Planning Practice Guidance — Planning Obligations