Varying a section 106 agreement after permission

You can vary a section 106 agreement at any time by deed, so long as the council agrees to it. The statutory route, where you apply to the authority and can appeal if it refuses, only opens once five years have passed since the obligation was entered into. That five-year gap decides most strategies. A scheme that needs a different tenure mix in month eighteen has to be negotiated, not put through a formal application, and the negotiation is where the room to move actually is.

Section 106A of the Town and Country Planning Act 1990 is the governing provision. It allows a planning obligation to be modified or discharged either by agreement between the authority and the person against whom it is enforceable, or by application after the relevant period. Everything else follows from which of those two you are using.

The two routes, and why the choice is usually made for you

Variation by agreement under section 106A(1)(a) has no waiting period and no prescribed form. It is a deed of variation, negotiated and executed like the original agreement, and it can do anything the parties will sign up to. Discharge an obligation entirely, change a trigger, substitute a sum, add a phasing clause.

The application route under section 106A(3) is different in kind. It is a formal request to the authority, available only after the relevant period, which section 106A(4) sets at five years beginning with the date the obligation was entered into. The authority then has three possible answers: the obligation continues unmodified, it no longer serves a useful purpose and is discharged, or it still serves a useful purpose but would serve that purpose equally well if modified in the way applied for.

Most developers never reach the second route, because most obligations that need changing are less than five years old. The deed is the working tool. The statutory route matters for legacy agreements on sites that have changed hands, where an obligation from 2015 still bites on a scheme nobody is building.

What the council wants in return for a deed

A deed of variation is a bargain, and the council's side of it is rarely just goodwill. Expect three asks as a minimum. The authority's legal costs, paid on an undertaking given before drafting starts. A monitoring fee if the varied obligation creates new monitoring work. And an updated set of parties, because obligations run with the land under section 106(3) and the title may have moved since 2019.

Officers also want the variation to be defensible on the file. A planning obligation must still meet the three tests in regulation 122 of the Community Infrastructure Levy Regulations 2010: necessary to make the development acceptable in planning terms, directly related to the development, and fairly and reasonably related in scale and kind. A variation that leaves an obligation failing any of those tests is one the council should not be asking for anyway. That cuts both ways, and it is the strongest argument available to an applicant who is being asked to keep paying for something the scheme no longer generates.

Where the change affects a matter that was part of the original planning balance, the officer will want a short report explaining why the development remains acceptable. The reasoning runs along the same lines as any other delegated decision, and it helps to write the variation up in the format an officer already uses, as set out in how a planning officer report is structured.

Where section 73 fits, and where it does not

Section 73 varies conditions. Section 106A varies obligations. They are separate powers and a section 73 permission does not touch the agreement at all.

This trips up more schemes than any other point on the subject. A section 73 permission is a new permission, so an obligation drafted to bind only the original permission may not attach to it. The fix is a short deed tying the existing agreement to the new permission, executed alongside the section 73 grant. The mechanics are set out in deeds of variation on a section 73 permission, and the drafting conventions in deed of variation: changing a section 106 agreement.

Check the definition of "the Permission" in your original agreement before assuming either way. Some are drafted widely enough to catch later section 73 grants. Many are not.

Evidence that moves a council

The evidence depends on what you are asking for, and the common mistake is to lead with the developer's problem rather than the planning position.

For a viability-driven change to affordable housing, you need an open-book appraisal to the standards in the RICS guidance, with inputs the council's own consultant can test. Expect the authority to appoint a reviewer at your cost and expect the benchmark land value to be the point of dispute. A late-stage review mechanism is often a more acceptable landing point than a permanent reduction, which is why late-stage review mechanisms turn up in so many varied agreements. The routes and the evidence each one needs are set out in varying a section 106 agreement.

For a timing or trigger change, the evidence is programme, not money. Show the sequence, the reason the original trigger cannot be met, and what protects the council's position if the development stalls.

For a contribution that has become unnecessary, the evidence is the receiving infrastructure. If the bus service the money was for has been withdrawn, or the school place has been provided from another scheme, say so and name the source. That is a regulation 122 argument, and it is much stronger than any appeal to fairness.

Appealing a refusal to modify

Section 106B gives a right of appeal where the authority determines that an obligation should continue without modification, or fails to determine the application. The appeal goes to the Secretary of State and is handled by the Planning Inspectorate.

Two practical points. The appeal only exists on the statutory route, so there is no appeal against a council simply declining to sign a deed. And the inspector applies the same statutory test as the authority, which is a narrow question about whether the obligation still serves a useful purpose. It is not a fresh look at the planning merits of the scheme, and arguments that belong in a section 73 application or a new application will not land.

Illustrative example. An obligation from 2016 requires a financial contribution towards a park extension the council has since delivered in full using other funding. Five years have passed, so the owner applies under section 106A(3) to discharge it. The useful-purpose test is met on the facts, because the purpose has been achieved by other means. Had the same owner instead argued that the contribution was now unaffordable, the test would have been the wrong one for the route chosen.

Drafting, costs and the funder's view

Budget for the council's solicitor as well as your own. On a straightforward variation of a single clause you are looking at a short document and a few weeks; on anything touching affordable housing, tenure or a registered provider's interest, allow months and expect a third set of lawyers.

Funders read the varied agreement, not the original. Two clauses get attention. The mortgagee exclusion provisions, because a lender will not advance against an obligation that could bind it on enforcement. And any indexation clause, because a deferred contribution restated in a 2026 deed may be re-based, which changes the sum actually payable. Deal with indexation expressly rather than leaving it to be argued later.

Negotiation points worth holding

Ask for the variation to be recorded against the title and for the authority to confirm the position in writing once completed. An unrecorded variation is a problem at the next sale.

Keep the scope narrow. Reopening a whole agreement invites the council to revisit obligations you were content with, and officers are entitled to look at the package as a whole once the deed is open. Name the clauses, amend them, and leave the rest alone.

Offer something. A shortened trigger elsewhere, a commitment to monitoring data, an earlier payment on a different head of terms. Variations that give the council a reason to say yes complete faster than those that only reduce what it receives.

Get the drafting instruction out early. The single biggest cause of delay is a variation agreed in principle at officer level in March and not instructed to the council's legal team until June.

Enter your postcode on PlanScope to see which supporting reports a revised scheme is likely to need before you reopen the agreement.

This is general guidance rather than legal advice. Check the position with your local planning authority or a qualified solicitor before relying on it. PlanScope provides AI-assisted draft reports for planning applications. Reports should be reviewed before submission. We do not guarantee planning approval.