How Long Do Section 106 Agreements Last? Timelines and Deadlines

S106 agreements don't have a fixed expiry date. They run with the land — meaning the obligations bind not just the original developer but any future owner of the site. In practice, this means councils can be monitoring obligations from agreements signed 15 or 20 years ago alongside new ones.

Here's how the timelines actually work and what planning officers need to track.

This covers England only. This is general guidance, not legal advice.

The Short Answer

An S106 obligation lasts until it's discharged — meaning the obligation has been fully performed. For financial contributions, that means the money has been paid, received, and (from the council's perspective) spent. For in-kind obligations, it means the infrastructure has been delivered and accepted.

There is no automatic expiry. An obligation that hasn't been triggered because the development hasn't commenced can sit dormant indefinitely.

Key Timelines in S106 Agreements

Planning Permission Duration

The underlying planning permission typically has a 3-year commencement condition: development must begin within 3 years of the permission date. If the developer doesn't commence, the permission lapses — and with it, the S106 agreement may become unenforceable, as the obligations are tied to the planning permission. The position can depend on the agreement's wording and whether any development has commenced, so seek legal advice before assuming an obligation has lapsed.

However, if the developer commences within 3 years (even by digging a trench), the permission is live and the S106 obligations remain binding for the life of the development.

Spend-By Deadlines

Financial contributions carry spend-by deadlines defined in each agreement — typically 5 to 10 years from the date the council receives the payment. These are the most critical timelines for monitoring officers. See S106 Spend Deadlines: What Happens When Developer Money Expires for the full process.

The 5-Year Modification Window

Section 106A of the Town and Country Planning Act 1990 allows any person bound by a planning obligation to apply to the LPA to have it modified or discharged after 5 years from the date the obligation was entered into.

The LPA can:

• Approve the modification or discharge
• Modify the terms (different from what was requested)
• Refuse to modify or discharge

If the LPA refuses, the applicant can appeal to the Planning Inspectorate.

This 5-year window is relevant because developers occasionally use it to reduce or remove obligations that were negotiated years earlier — particularly where market conditions have changed or the development has shifted.

What monitoring officers should watch for: Applications to modify obligations on agreements that are 5+ years old. These may affect financial contributions you're expecting to receive or in-kind obligations you're tracking.

Phased Development Timelines

Large developments are delivered in phases over 10–20 years. Each phase may trigger different S106 obligations:

• Phase 1 (years 1–3): Commencement triggers, initial infrastructure contributions
• Phase 2 (years 4–7): Occupation-based triggers, affordable housing delivery
• Phase 3 (years 8–12): Remaining triggers, final contributions
• Ongoing: Maintenance obligations, monitoring fees

This means your S106 register needs to track the development phase alongside each obligation's status. An agreement signed in 2020 may have Phase 3 triggers that won't fire until 2032.

What This Means for Monitoring

Long-Running Agreements Need Active Monitoring

An agreement signed in 2015 with a phased development is still generating obligations in 2026. If your monitoring relies on institutional memory rather than structured records, obligations from older agreements are the ones most likely to fall through the cracks — especially if the officer who set up the monitoring has moved on.

Practical steps:

• Review all agreements older than 5 years annually
• Check whether triggers have been reached but not recorded
• Verify that financial contribution records are complete (receipt dates, indexation, allocation)
• Confirm whether the development is still progressing or has stalled

Dormant Agreements

Some S106 agreements are attached to permissions that were never implemented. The permission hasn't lapsed (commencement occurred) but the development has stalled. The obligations are technically still binding.

These dormant agreements shouldn't consume active monitoring time, but they should be flagged in your register. If the development restarts (which can happen years later when the site is sold), the obligations reactivate.

Succession in Title

S106 obligations run with the land, not with the developer. If the site is sold to a new owner, they inherit the obligations. This matters for monitoring because:

• Your developer contact may change without notification
• The new owner may not be aware of the obligations
• Invoicing a developer who no longer owns the site creates delays

When you become aware of a site sale, update your register with the new owner details and re-establish contact for trigger monitoring and invoicing.

Common Questions from Officers

Can we enforce an obligation from a 15-year-old agreement? Potentially, yes — if the obligation hasn't been discharged and the trigger has been reached. S106 obligations run with the land and are not subject to the standard six-year limitation period for simple contracts. However, enforcing older obligations can involve practical difficulties (poor records, changes in site ownership, unclear trigger evidence), so seek legal advice before pursuing enforcement on historic agreements.

What if the developer has dissolved? The obligation runs with the land. Identify the current landowner and enforce against them.

Can we discharge a completed obligation? You can confirm in writing that an obligation has been satisfied. Some councils maintain a discharge log alongside their S106 register. This is good practice — it prevents confusion about whether an obligation is still active.

What happens to an agreement if the permission is superseded by a new application? The original S106 agreement remains unless it's specifically discharged or replaced by a new agreement attached to the new permission. Check whether the new permission's S106 supersedes or supplements the original.

For the complete monitoring process, see The Complete Guide to S106 Monitoring for Planning Officers.

Sources

• Town and Country Planning Act 1990, Section 106
• Town and Country Planning Act 1990, Section 106A (Modification and Discharge)
• GOV.UK — Planning Obligations Guidance