Sell biodiversity units as a land manager
Source: gov.uk (2025-06-18)

How to sell biodiversity units to developers for biodiversity net gain: explore the market,  register a gain site and record allocations.

‘Land manager’ refers to these different roles across the biodiversity net gain (BNG) guidance:
- landowner
- farmer
- estate owner
- habitat bank operator
- facilities, property or estate manager
- land agent
- land advisor
- planning authority using land they own
- developer using land they own
Why you may choose to sell off-site biodiversity units

Under mandatory BNG legislation (https://www.gov.uk/guidance/understanding-biodiversity-net-gain), developers must deliver 10% BNG.

If developers cannot achieve BNG on their own sites, they will have to make off-site gains by using off-site biodiversity units. Off-site means outside the red line boundary of the development that has planning permission requiring BNG.

You can sell biodiversity units to developers on:
- land you own
- a landowner’s land with their permission
For the purposes of BNG, biodiversity value is measured in standardised biodiversity units.

Your land will contain a number of biodiversity units, depending on factors like its:
- size
- quality
- location
- type
In order to sell units, you will need to follow various steps, including:
- using the statutory biodiversity metric (https://www.gov.uk/guidance/biodiversity-metric-calculate-the-biodiversity-net-gain-of-a-project-or-development) to measure the biodiversity value of your existing land, and calculate how many units habitat creation or enhancement could generate on the land
registering your units as a biodiversity gain site on a national public register
- recording on the register the allocation of the off-site gains to a developer, who will use it to achieve their BNG
Selling in the BNG market is a choice for land managers. It is a potential source of revenue and could fund nature recovery work on your land. You may, for instance, choose to generate and sell biodiversity units alongside farming, creating income from land that may otherwise be unsuitable for food production.

Obligations and options when you sell biodiversity units for off-site gains

Obligations

Once created or enhanced, the habitat must be maintained for at least 30 years.

The land owner is legally responsible for creating or enhancing habitat, and managing that habitat for at least 30 years to achieve the target condition.

The details of your obligations will depend on:
- which option you choose for selling your units
- what you agree in the legal agreement and habitat management and monitoring plan (HMMP)
Options for selling biodiversity units

There are 3 main ways you can sell to developments looking for off-site biodiversity units. Make an informed decision based on what is best for the land owner.

1. Sell biodiversity units independently

You’ll need to take full responsibility for following all the steps in this guidance.

2. Work with one or more partners

You can team up with a local non-governmental organisation (NGO) or other land managers. Depending on how many people you work with, you may be able to create large habitat banks. You would then sell biodiversity units as a group. As a group, you still need to follow all the steps in this guidance.

If you choose this option, you need to make sure you work out:
- who is responsible for which activities
- how you’ll share payments
3. Use a habitat bank operator

A habitat bank operator could help you do things like find a buyer, legally secure your land and register your gain site.

Either the operator or the land manager may do the habitat creation, enhancement and management, as well as any reporting. You will need to agree all the details of who does what in your contract with the operator.

Make sure you check the contract with the operator to find out:
- who is responsible for which activities
- when and how you’ll receive payment
- what will happen if the habitat doesn’t reach the target habitat condition
- what will happen if no units are sold within the period of the legal agreement
- what will happen if the habitat bank operator ceases trading
You can search online to find habitat bank operators. Farmers’ organisations and publications may advertise them.

Check if you need a screening decision for BNG

Landowners should check if they need a screening decision before registering their land as a BNG site (https://www.gov.uk/government/publications/changing-uncultivated-semi-natural-and-rural-land-when-you-need-permission/check-if-you-need-a-screening-decision).

Combining BNG with other environmental payments

If you’re already receiving payment for creating or enhancing habitat, consider how you can combine BNG with other environmental payments (https://www.gov.uk/guidance/combining-environmental-payments-biodiversity-net-gain-bng-and-nutrient-mitigation).

When you cannot sell biodiversity units

You cannot sell biodiversity units or combine them with other environmental payments when you’re already required to create or enhance habitat for:
- restocking trees
- marine licensing
- remediation under the environmental damage regulations (https://www.legislation.gov.uk/uksi/2015/810/contents)
Selling biodiversity units on protected sites

You may be able to enhance a protected site (https://www.gov.uk/guidance/protected-areas-sites-of-special-scientific-interest) and sell the units for BNG. You must get consent from Natural England (https://www.gov.uk/government/publications/request-permission-for-works-or-an-activity-on-an-sssi) before you start work and renew consent as required.

You must ensure that any protected species licences (https://www.gov.uk/guidance/wildlife-licences) required are in place before works commence.

Non-intertidal protected sites

You can enhance features that are not specified as one of the designated features of the protected site. You must not do something which could adversely affect a designated feature.

Intertidal protected sites

You can enhance any intertidal habitat on a protected site, including the features for which the site is designated, provided this is acceptable to the consenting organisation.

How to sell biodiversity units

This is an example order of steps, but the order of some steps is flexible.

You can register your gain site:
- before recording the allocation of units to a developer
- at the same time you record the allocation
You can register your gain site and allocate units to a developer:
- before you sell your units
- at the same time as you sell your units
- after you sell your units
The 30-year BNG maintenance period requirement starts from the completion of habitat enhancement works, as defined in your legal agreement.

You can begin habitat creation, enhancement and management on a gain site before allocating off-site units on it. This is called habitat banking. Or you can allocate the units and then begin the habitat work as soon as possible.

You can sell different units on one gain site to different developers. You would need to follow the steps in this guidance for each allocation of units to a development.

1. Find out how many units you could sell and the habitat types you could create

You should consult a qualified ecologist who will do a survey and measure the biodiversity value of your existing habitat before enhancement. There is guidance on how to do this, using the biodiversity metric (https://www.gov.uk/guidance/biodiversity-metric-calculate-the-biodiversity-net-gain-of-a-project-or-development). Seek advice from relevant professionals (for example ecologists or land advisors) on your options to enhance the value of the habitats on your site, and to understand how many units you could sell.

You will be able to sell more units per hectare if you carry out the strategic actions given for your location in your local nature recovery strategy (LNRS) (https://www.gov.uk/government/publications/local-nature-recovery-strategies-areas-and-responsible-authorities). You should include these strategic actions in site habitat management and monitoring plans. If your LNRS is not yet published, you can use the draft strategy, or another strategy your local planning authority (LPA) recommends. You can find your LPA (https://www.gov.uk/find-local-council).

You can consider:
- creating and enhancing habitats to meet the BNG requirements of a specific development, or
- creating and enhancing habitats that are appropriate to your site conditions and locally in demand, before matching with a development
2. Price your units

To set a price for your units, you should think about the cost of, for example:
- initial creation and enhancement of habitats
- management of the land covering at least 30 years
- monitoring and reporting
- ecologist or other expert’s costs
- insurance
remedial work to correct any habitat management failures
- machinery, tools and other staff to carry out the tasks
- inflation
- consulting experts to review your legal agreement
It is important to ensure that your pricing covers all of these costs over a minimum of 30 years to meet the obligations in your BNG legal agreement. You may be able to find biodiversity unit pricing information in online marketplaces, or through your local authority and land agents. Be mindful that different locations and types of projects will have pricing variations, and your prices should be based on your own costs to deliver the units.

You should price units based on the costs incurred when doing the habitat enhancement and not the number of units habitats will generate. A habitat enhancement may be worth more units to one developer than another. The land manager’s price for the work is fixed, but the price per unit will go up or down depending on distance to the development site.

Defra and Natural England do not set off-site biodiversity unit prices. Statutory biodiversity credit prices (https://www.gov.uk/guidance/statutory-biodiversity-credit-prices) are not guideline prices for biodiversity units sold in the off-site private market.

3. Secure the units with a legal agreement

Before you can register your gain site, you must have a legal agreement (https://www.gov.uk/guidance/legal-agreements-to-secure-your-biodiversity-net-gain). This could be a planning obligation with a local authority or a conservation covenant with a responsible body. The legal agreement must secure habitat enhancement and maintenance for at least 30 years. You make legal agreements with your local planning authority or another responsible body. They detail the habitat works you are committing to and the outcomes to be achieved.

You should also prepare a habitat management and monitoring plan (HMMP) (https://www.gov.uk/guidance/creating-a-habitat-management-and-monitoring-plan-for-biodiversity-net-gain) and agree this with your LPA or responsible body, depending on which type of legal agreement you enter into.

4. Find a buyer for your units, if you do not have one already

To explore the private market, you could:
- search online for marketplaces
- consult a land agent, broker or another consultant
- speak with developers you already have links with
- speak with your LPA, who may be able to signpost you to buyers in the market and in some cases may act as informal brokers
- speak with habitat bank operators who would try to organise a sale for you
Off-site BNG is a private market and there is no guarantee you will find a buyer.

5. Sell your units

It is up to you how you arrange the sale, including any contract of sale you may choose to have with the buyer. You may want to seek legal advice on making the sale.

When planning a contract of sale, you should consider including:
- the number and type of units to be registered and allocated to a development (see steps 6 and 7)
- your commitment to record the allocation of units
Prices and payment terms should be agreed between you and the buyer.

The developer may not want to complete the sale of units until they are confident their biodiversity gain plan (https://www.gov.uk/guidance/submit-a-biodiversity-gain-plan) will be approved.

You’ll need to agree whether you’ll get paid by:
- lump sum
- staged payment
- results
6. Register your gain site

You must register your land as a biodiversity gain site (https://www.gov.uk/guidance/register-a-biodiversity-gain-site) on the national biodiversity gain sites register (https://draft-origin.publishing.service.gov.uk/guidance/search-the-biodiversity-gain-sites-register). This is operated by Natural England.

The register lists sites that are providing biodiversity units, enabling developments to achieve BNG. The purpose of the register is to show how and where developments are improving biodiversity off-site. It also prevents ‘double counting’, which would happen if the same units were assigned to multiple developments. Gains from sites on the register may be allocated to specific development projects to help them achieve their biodiversity gain target. The register does not contain contact details of available gain sites and is not a ‘matchmaking’ service to connect buyers and sellers. Buyers and sellers will find each other through the private market.

If you’re registering someone else’s land, you must provide a signed, dated written statement from them as proof that you can do this on their behalf.

Personal information provided as part of registration, such as names, addresses and contact information, will not be published in the public register.

7. Record the allocation of off-site units to a development

You (or the developer, with your permission) will need to apply to record the allocation of off-site biodiversity gains to a development (https://www.gov.uk/guidance/record-allocation-of-off-site-biodiversity-gains-to-a-development). In order for a developer to have a biodiversity gain plan approved, the LPA will need evidence that the land has been allocated to the development. In order to provide that evidence, the allocation will need to be recorded on the register.

8. Manage the habitat for at least 30 years

Off-site units must be maintained for at least 30 years following the completion of habitat enhancement works, as defined in your legal agreement.

If habitat creation, enhancement and management work has not started by the time you record the allocation of off-site units, this should start within 12 months of allocation.

Further sources of information

Defra’s land use blog has published step by step BNG flowcharts for land managers (https://defraenvironment.blog.gov.uk/2023/11/15/biodiversity-net-gain-for-land-managers-step-by-step-flowcharts/).

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