Selling F gas or equipment

Your responsibilities as a fluorinated gas (F gas) wholesaler or reseller.

Record keeping

You can only sell F gas to customers that:

  • hold relevant certificates and qualifications
  • employ people that hold the relevant certificates and qualifications

If you sell F gas to a customer who will install, service, maintain or repair equipment containing F gas (or uses F gas to function), you must check that the customer holds individual qualifications or employs people holding a qualification.

If they’re doing this work on behalf of someone else, you must check that the customer has relevant company certificates.

You must keep records of:

  • the customer’s certificate number
  • quantities of F gases they buy

You must keep these records for at least 5 years and show them to your regulator when asked.

A person without qualifications may collect, transport or deliver F gases.

Get a letter of assurance from F gas customers

You must get a letter of assurance from every customer you sell F gas to. You need this letter if you’re a:

  • wholesaler selling to a reseller
  • wholesaler or reseller selling to a certified or qualified engineer
  • wholesaler or reseller giving gas to a customer for collection, transport or delivery, that has been bought by a certified or qualified engineer

You can download a F gas customer letter of assurance template (ODT, 17.3KB) and ask your customers to complete it.

In the letter, the customer must confirm that they are permitted to buy or collect F gas and that:

  • they will not release F gas into the atmosphere intentionally, unless technically necessary for the use of the F gas
  • they will take all steps to prevent F gas leaks

Get a letter from end users of F gas equipment

If you sell stationary refrigeration, air conditioning, heat pump and fire protection systems, you must get a letter from the end user to confirm the details of the qualified technicians they are using to:

  • install
  • service
  • repair
  • decommission

See guidance on:

You don’t need this letter if the equipment is hermetically sealed - that is if:

  • a part of the product containing F gas is permanently sealed, for example welded or brazed shut, even if it has capped valves or service ports
  • the product has a tested leak rate of less than 3g per year

It is against the law to buy F gas or sell F gas to a person if the person buying does not have the correct qualifications or certificates. If you do, you could receive a civil penalty. See the Environment Agency enforcement sanctions policy.

If you see someone breaking the law on F gas, report it to

Published 21 August 2019