The NFU has urged farmers to be extra vigilant following reports of scam phone calls pretending to be calling from the union's head quarters.
The NFU, as well as NFU Cymru, have received reports from members who have been the target of scam phone calls purporting to be selling insultation.
The union said these companies have no relation to itself, NFU Cymru or NFU Energy and should be ignored.
"If they know your supplier, supply number and address it may still not be us, this information is publicly available on the electricity database," the NFU said.
"If you suspect that it isn’t NFU Energy ask us to confirm your unique reference that we hold.
"If you’re unsure of your reference or if they cannot confirm it, the safest thing to do would be to end the call and call us directly on 024 7669 8885.
"We really won’t mind if it was us, as we understand that it’s better to be safe than sorry."
The NFU added: "If they claim to be your supplier but cannot confirm your account number, terminate the call and call back the number on your bill to speak to the supplier directly. Alternatively, call us and we will help as best as we can.
"If you have caller display, look at the number or dial 1471 after the call. NFU Energy call from 024 7669 6512.
"Be very suspicious if it is from a mobile (starting 07) and even more so if it’s unavailable or withheld."
