Overage agreements explained: when is an overage payment triggered?
1st May 2026
Author: George Flanders
If you have sold land subject to an overage agreement, or you are developing land affected by one, it is important to know when an overage payment may be triggered.
An overage agreement, sometimes called a clawback agreement, allows a landowner to share in any future increase in the value of land after it has been sold. This often happens where planning permission is granted for residential development, but it can also apply in other situations.
With recent changes in planning policy and continued pressure on housing land supply, many landowners and developers are taking a fresh look at existing arrangements. If you have entered into such an agreement in the past few years, it may be that an overage payment will soon be triggered given the current planning landscape. Agricultural and Commercial Property specialist George Flanders explains when and how an overage payment can be triggered.
What is an overage agreement?
In simple terms, an overage agreement gives the seller of land the right to receive an additional payment if a future event increases the land’s value.
That future event is usually linked to planning permission. For example, land that had limited value when it was sold may become significantly more valuable once planning permission is granted for housing. An overage agreement is designed to ensure that the original landowner shares in that uplift.
These agreements can be valuable for both sides. A landowner has the chance to benefit from future development potential, while a buyer or developer may be able to proceed with the transaction without paying the full development value upfront.
When is an overage payment triggered?
The answer will depend entirely on the wording of the agreement.
In many cases, payment is triggered when planning permission is granted. In others, it may only become payable when that permission is implemented or when the land is sold on with the benefit of planning permission.
This distinction matters.
For developers, a payment triggered by the grant of planning permission can create an immediate financial commitment. That means funding needs to be planned carefully before a planning application is submitted. If permission is granted and payment falls due quickly, cash flow can become an issue.
For landowners, it is important to check whether the agreement requires the developer to keep you informed about planning applications and their progress. If those reporting obligations are included, they can help you monitor whether an overage payment is likely to arise and whether the agreement is being followed properly.
It may also be sensible to keep an eye on the local authority planning portal so that you are aware of any application affecting the land.
When does the payment become due?
Once an overage payment is triggered, the agreement should also state when it becomes payable.
Where payment is triggered by the grant of planning permission, it is often deferred until at least six weeks after permission is granted to allow time for any challenge to the decision. In other cases, the agreement may provide for payment within a set number of working days following the trigger event.
As ever with overage, the detail matters. A clause may appear simple at first glance, but timing can have a significant impact on both landowners and developers.
How is an overage payment calculated?
Most overage clauses use a formula based on the uplift in value.
The standard formula is:
(a – b) x c
where:
a = enhanced value, being the value of the land with the benefit of planning permission
b = base value, being the value of the land before planning permission was granted
c = the agreed percentage entitlement
Although this appears to be a relatively simple formula, the definitions of enhanced value and base value can be heavily negotiated. Small changes in drafting can significantly increase or reduce the amount of an overage payment.
It is therefore important to check the agreement carefully for any matters that are to be assumed or disregarded when enhanced value and base value are determined. It is often sensible to take valuation advice from a chartered surveyor alongside legal advice so that the calculation can be properly understood.
Beyond the basic formula, it is also common for parties to agree that the planning costs of obtaining planning permission are deducted from any overage payment so as to reimburse the developer for their efforts.
That is why it is important to review the wording carefully and, where necessary, take advice from a suitably qualified valuer as well as a Solicitor.
Does the overage end after the first payment?
Not always.
One of the most important questions is whether the overage falls away after the first trigger event, or whether it continues for the full overage period.
This matters because a first planning permission may not reflect the highest value of the land. If the overage is released too early, a landowner may miss out on further value created by a later and more valuable permission.
For that reason, many overage agreements are drafted so that the land remains subject to overage for a set number of years, rather than ending after the first payment.
That said, the practical position can change once a development is complete. If a site has been fully built out, there may come a point where the parties agree that the overage should be formally released. Again, this will depend on the wording of the agreement, the type of development and the stage the development has reached.
What should landowners and developers do now?
If you are a landowner, now is a good time to check:
- what event triggers payment
- whether you are entitled to updates about planning activity
- how the payment is calculated
- whether the overage continues after the first permission or payment
If you are a developer, you should review:
- when payment becomes due
- whether planning costs can be deducted
- what notice requirements apply
- whether the agreement could affect future phases or revised permissions
How we can help
Overage agreements often turn on detailed drafting and careful interpretation, so it is important to take advice at the right time.
That may be before you enter into an agreement, so that the terms properly protect your position. It may be when the triggering of an overage payment is anticipated, so that the correct procedure is followed. It may also be when an overage payment has already been triggered, so that payment and any future entitlement are dealt with appropriately.
At Butcher & Barlow, we advise both landowners and developers on overage agreements. We provide clear, practical advice to help you understand your position, protect your interests and make informed decisions about the next steps.
If you anticipate an overage payment becoming due in the near future, or if you have any questions about your obligations under an existing agreement, please contact our Agricultural and Rural Affairs Team or complete our online enquiry form.
George can be contacted on 01606 334309 or emailed at gflanders@butcher-barlow.co.uk
The information in this article was correct at the time of publication. The information is for general guidance only. Laws and regulations may change, and the applicability of legal principles can vary based on individual circumstances. Therefore, this content should not be construed as legal advice. We recommend that you consult with a qualified legal professional to obtain advice tailored to your specific situation. For personalised guidance, please contact us directly.