Details of who needs to register can be found on GOV.UK:

1. Any person or business using PPPs or their adjuvants in a professional capacity
   Register as a professional user
   
   
2. Any business that produces, manufactures, processes, stores, distributes or sells PPPs for professional use
   Register as a business that places them on the market
   
   
3. Any business that sells amateur PPPs
   Register as a seller

Any business or other organisation that started working with PPPs professionally more than 3 months ago should have registered already and must do so as soon as possible.

New professional users and businesses should register within 3 months of starting business.

If you have already registered, you do not need to take any further action.

Defra is collecting information from businesses in Scotland and Wales on behalf of Scottish and Welsh Governments. Businesses in Northern Ireland should not register with Defra as Northern Ireland has created its own regulations.

See the DEFRA policy statement for more details.