Residents in Eastbourne are now receiving the £150 energy rebate in their accounts, thanks to the "tireless efforts" of council staff.
With 37,895 households to assess, the council team had to create an automated validation process that ensures payments are only made to eligible residents.
Some 26,775 direct debit payers are being processed first, followed by 11,120 who use alternative payment methods.
The total payments made in Eastbourne over the last few days is £3,787,500 - confirmation letters are being sent to households.
Councillor David Tutt, Leader of Eastbourne Borough Council, said: "The cost of living crisis is bringing unprecedented pressure on families, particularly the most vulnerable in our town.
"The £150 rebate is a welcome step, but as I have made clear previously, the government could give people in real need the support they are desperate for by agreeing a windfall tax on the energy companies.
"BP announced today nearly £5 billion in profits for just the first three months of the year, which makes the decision not to bring in a windfall even more difficult to understand."
Where the automated payment system flags up an account as requiring more information or clarification can be made, council officers will write to the council taxpayer concerned - the council will not telephone residents and ask for details.
Councillor Tutt added: "I would like to thank our officers for their tireless efforts to get this payment system into place so quickly. They also set up an award winning system for paying grants during the pandemic and so it is no surprise that they have excelled with this latest initiative."
To find out more about the Energy Rebate Scheme or set up a direct debit visit lewes-eastbourne.gov.uk/council-tax/energy-rebate-scheme