People are being warned to watch out for council tax rebate fraudsters, who are exploiting desperation to receive the living cost crunch payment to carry out scams.
Millions of households up and down the country are still awaiting the £150 payments, that are set to land in council tax payers' accounts from April.
But the rebate scheme is already being used by cold-calling scammers trying to fleece people, according to some local authorities - including one in London.
Southwark Council warned on Twitter: "Fraudsters are calling residents and asking for bank details to receive the council tax rebate.
"The council will not call you to ask for these details - we will start contacting residents by letter or email later this month."
Durham County Council warned: "SCAM ALERT - We understand that callers, claiming to be from Durham County Council, have asked residents for their bank details in order to process the £150 Council Tax Rebate.
"You will never be asked for bank details over the phone."
The Government announced the rebate support earlier this year in response to soaring energy bills, with payments administered by local authorities for all households in council tax bands A to D.
Councils have urged residents to be alert to the cold-calling scams, stressing they would never ask for bank details over the phone.
The Local Government Association (LGA) said anyone who unexpectedly receives a text, email or phone call seeking information or payment should not give out personal information, including bank details, click any links or respond until they can be sure it is genuine.
If in doubt, householders should find the details online of the organisation claiming to be in contact and check with them directly.
The pandemic saw a sharp increase in scams, which included promises of a payment from HM Revenue and Customs to support individuals during the lockdown or offers of a vaccination booking for a fee.
Mohan Iyengar, vice-chairman of the LGA’s Safer and Stronger Communities Board, said: “Councils are working hard to ensure eligible residents receive their energy rebate payments as soon as possible, however criminals are becoming increasingly sophisticated in their attempts to take advantage of the financial worries people are facing and as a result many of these scams look legitimate on first impression.
“Anyone can fall victim to a scam, and we urge people of all ages to brush up on the tell-tale signs, and the support available to those who need it.
“If you get sent a message that you believe to be fraudulent, you can report it to your mobile phone provider or by forwarding the message to 7726, a free reporting service provided by phone operators.
“You should also report the scam to Action Fraud to help others avoid falling victim in the future.”
How and when will I get the £150 council tax rebate?
All households that pay council tax by direct debit will receive the payment directly into their bank account.
Those who do not pay their council tax by direct debit will be sent a letter with details of how to claim.
Some councils have said the payments could arrive in May, as they urged residents to sign up for direct debit council tax billing so their rebate would arrive in their accounts automatically.
Council tax bill-payers are being urged to check their local authority's website to find estimates of when the £150 is likely to be paid into their accounts.