Bats: licence to interfere with bat roosts (CL21)

Apply to become a registered consultant to disturb or capture bats or to damage or destroy roosts of low conservation significance.


Bats: low impact class licence application form (CL21)

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You must register sites to carry out works that have a temporary or low effect on certain bat roosts in England.

You must apply to become a registered ecological consultant (‘registered consultant’) before you’re able to register sites. You can only apply as an individual registered user, not as a group or consultant practice. This makes sure the criteria needed for this licence are met by every consultant.

Under this bat low impact class licence (CL21) you can disturb and capture bats or damage and destroy bat roosts, if your actions affect no more than:

  • 3 roosts of low conservation importance (known as ‘low conservation significant roosts’), such as feeding roosts, day or night roosts or transitional or occasional roosts
  • 3 of the more common bat species in small numbers at a roost (includes pipistrelle, soprano pipistrelle, brown long-eared, whiskered, Brandt’s, Daubenton’s and Natterer’s)

You must attend a 2-day training course and pass the assessment to get a registration number. You’ll then be able to register sites to carry out works under CL21.

Criteria to get registered

You can apply to become a registered consultant if you meet the following criteria.

Experience with mitigation licences

You’ll need to show you were the ecologist involved on bat licences for at least 5 bat species, to include at least one species from the groups:

  • Pipistrellus
  • Plecotus
  • Myotis and/or Rhinolophus

You must also meet one of these 3 conditions (known as ‘scenarios’).

Scenario 1

You’ve held at least 5 mitigation licences granted in the last 4 years, one of which has been issued in the last 12 months.

Scenario 2

You’ve held at least:

  • 3 mitigation licences granted in the last 4 years, one of which has been issued in the last 12 months
  • 3 science or research licences over a 4-year period

Scenario 3

You’ve held at least:

  • 2 mitigation licences granted in the last 4 years, one of which has been issued in the last 12 months
  • 2 science or research licences over a 4-year period

You must also be:

  • currently registered as a volunteer bat roost visitor trainer
  • an active member of a local bat group for at least 18 months

If you’ve had a career break in the last 4 years you must meet the same criteria for either scenario over a 5-year period.

Other criteria

You must also show you’ve:

  • held a current level 2 (minimum) bat class survey licence for at least 3 years

  • evidence that you’re a full member of a professional body (or an associate member for at least 3 years) such as the Chartered Institute of Ecology and Environmental Management (CIEEM), The Institute of Environmental Management and Assessment, The Chartered Institute of Water and Environmental Management or the Royal Institution of Chartered Surveyors

On bat licences that you’ve held you must have:

  • carried out the majority of surveys
  • carried out the majority of impact assessments
  • designed the majority of project plans to include compensation and mitigation measures
  • undertaken the majority of the licenced works
  • worked on a range of roost types including higher conservation significant roosts not covered by CL21 (such as a maternity roost or hibernation roost)
  • demonstrated experience and understanding of a range of licensable methods, such as using endoscopes
  • submitted all bat survey licence return forms
  • met the deadlines and conditions for submitting licence returns which include full details of actions taken under licence
  • kept your skills and development up to date with continuing professional development
  • had no convictions of wildlife-related or animal welfare offences in the last 5 years

Disability consideration

Email Natural England at if you have a disability that makes it difficult for you to meet these criteria. Natural England will consider your request on its merits.

Apply to register

Complete the form CL21 (attached to this page) and email it to Natural England

You may need Adobe Reader to fill in the form - see Get the right software.

Natural England will decide if you’re eligible to become a registered consultant and tell you by email within 15 working days. Natural England will then invite you to the next available 2-day training workshop. If you fail to meet the criteria you’ll be told why.

Compulsory training

You must attend the full training to get the registration number you need to register sites and carry out works under CL21. You’ll cover all the requirements of holding CL21, such as:

  • understanding the legal requirements of the licence
  • how you use the licence
  • how to complete registration and return forms

You’ll need to pay for the training and overnight accommodation. You’ll get full details in your invitation email.

The training is organised and run by the CIEEM and Natural England. Neither organisation will profit from running the courses. It will be run on a full cost recovery basis.

Get the right software

The application form is interactive (one that you complete on screen) and you must use Adobe Reader to complete it. Downloading Adobe Reader is free. Download the latest version of Adobe Reader.

Contact Natural England if you have problems with this.

Published 6 April 2017
Last updated 10 January 2018 + show all updates
  1. Replaced application form with updated version.
  2. First published.