Bats: survey or research level 4 licence (CL20)
Source: gov.uk (2025-10-17)

Register for a licence to survey bats using harp traps for scientific, research, or educational purposes including informing development projects - and report actions taken under the licence.

This licence allows you to disturb or capture bats by hand or using:
- harp traps – for development surveys only (used for a maximum of 3 days at any one site)
- static hand-held nets
- acoustic lures
- endoscopes
- torches
You need a:
- level 1 licence (https://www.gov.uk/government/publications/bats-survey-or-research-licence-level-1) if you only need to disturb roosting bats using a torch
- level 2 licence (https://www.gov.uk/government/publications/bats-survey-or-research-licence-level-2) to handle bats and use static hand-held nets or an endoscope
- level 3 licence (https://www.gov.uk/government/publications/bats-survey-or-research-licence-level-3) to use mist nets and acoustic lures
For survey, research or conservation work not covered by this licence you must apply for either:
- an individual licence (https://www.gov.uk/government/publications/bats-licence-to-disturb-or-take-bats-for-science-or-conservation)
- a level 1 licence (https://www.gov.uk/government/publications/bats-survey-or-research-licence-level-1)
- a level 2 licence (https://www.gov.uk/government/publications/bats-survey-or-research-licence-level-2)
- a level 3 licence (https://www.gov.uk/government/publications/bats-survey-or-research-licence-level-3)
For development work affecting bats, you must apply for a mitigation licence (https://www.gov.uk/government/publications/bats-apply-for-a-mitigation-licence).

You can disturb but not handle hibernating bats.

You must release all bats at the place where they were captured immediately after being examined.

If you are registered on the level 4 licence you will not need the level 1 or level 2 licences because it covers the same methods. You will need a level 3 licence to use harp traps.

Register with Natural England

Before you can use this licence, you must register with Natural England

Register for a class licence to survey bats (CL20) (https://submit-form-to-defra.service.gov.uk/form/apply-for-a-class-licence-to-survey-protected-species/which-species-do-you-want-to-apply-for-a-class-licence-for)

Natural England will confirm your registration in writing, usually within 30 working days. You must not carry out any licensed activities until you receive written confirmation of your registration.

What you need to pay

It costs £104 to register for a new CL20 licence.

It costs £35 a year to continue your registration.

You must declare the intended use of the licence on your registration form. To continue your registration, you must declare how you used the licence in the past year on your annual survey return. This will determine if you need to pay, such as if you are going to survey bats for development projects.

Natural England will refund unsuccessful applications.

When you do not need to pay

You do not need to pay if the licence is only used for:
- voluntary purposes – any work you do is unpaid and you are registered with an organisation, charity or local recording group as a volunteer
- conservation, science or research purposes and research related to the protected species is carried out by a student or employee of an academic institution or research body
How to pay

You can pay using a bank card. Follow the GOV.UK Pay link on the registration form (https://submit-form-to-defra.service.gov.uk/apply-for-a-class-licence-to-survey-protected-species) or survey return form (https://submit-form-to-defra.service.gov.uk/form/submit-a-bat-survey-licence-return).

Read the terms and conditions for paying for a wildlife licence (https://www.gov.uk/government/publications/terms-and-conditions-for-paying-for-a-wildlife-licence).

References

You need to complete a reference to support a survey or research licence form (https://www.gov.uk/government/publications/reference-to-support-a-protected-species-licence) when you register for this licence if you:
- have not held a licence for the species or a similar species for the last 3 years
- have a licence but want to add new methods
Report actions taken under the licence

You must report in a bat survey licence return any actions that are taken under this licence.

Report your actions from 1 November to 31 October each year, and submit the form by 30 November each year, even if you’ve taken no action or did not find any target species. If you need to submit it outside these dates (for exceptional reasons only) email xxx@xxx.xx (mailto:xxx@xxx.xx).

You’ll need to provide the names of any accredited agents who carried out the surveys on your behalf.

You must tell us about all the surveys where you or your accredited agents found bats when using the licensable methods. For CL20 these will be surveys where you:

captured bats by hand or hand net, or using a harp trap

disturbed roosting bats with a torch or endoscope

used an acoustic lure

For each site where you disturbed or captured bats using the licensable methods, you must record the:

location of the site (10 figure Ordnance Survey grid reference and county)

start and end date of the period that surveys took place at each site

purpose of your surveys

total number of each species of bat that were captured or disturbed using each licensable method over the entire survey period

peak count of each species of bat recorded roosting on the site in any single survey

peak count of each species of bat captured across all harp traps on any single survey

use of acoustic lures

You’ll also need to report whether you and any accredited agents followed best practice when using the licence.

You do not need to tell us about surveys:

where you did not use the licensable methods, for example, a nocturnal survey where you did not capture or disturb any roosting bats

that were carried out under a different licence, such as a bat mitigation licence or individual project licence

where you were an accredited agent or assistant on another person’s survey class licence or individual project licence

If you hold both a CL19 and CL20 licence, complete one bat survey licence return form to cover both licences.

Submit a bat survey licence return (https://submit-form-to-defra.service.gov.uk/form/submit-a-bat-survey-licence-return)

You must also send your results to the Local Record Centre. You can do this by recording your results on the iRecord website (https://www.brc.ac.uk/irecord/) or contacting the Local Record Centre (https://www.alerc.org.uk/contact.html).

Using your licence for another year

By reporting your actions, you can continue to use the licence for the following reporting period. If you will use the licence for surveys to inform development projects, you will need to pay £35 to continue your registration for another year.

Get help

If you need help with registering for a class licence or completing your survey licence return form, contact xxx@xxx.xx (mailto:xxx@xxx.xx).