Millions of low-income households will receive the next instalment of cost-of-living payments between 31 October and 19 November.
Eight million people on means-tested benefits, such as Universal Credit, will receive £300 directly, without the need to make a claim.
It is the second of three instalments that will eventually total £900.
Separate payments have been made to some people with disabilities, and will be paid to pensioners in the winter.
More than six million people with disabilities received £150 during the summer. At some point in the winter, over eight million pensioners will receive an extra £300.
Work and Pensions Secretary Mel Stride said: "The best way we can boost bank balances is by bearing down on inflation, but as we get there, we are ensuring the most vulnerable households are cushioned from high prices with a further cost-of-living payment."
All will be paid directly into eligible recipients' bank accounts, and people are being warned about scammers using the situation to try to trick people into handing over personal information.
People eligible for payments who are claiming tax credits only will get £300 from HM Revenue and Customs (HMRC) between November 10 and 19.
The payment reference for bank accounts will be the recipient's national insurance (NI) number followed by "DWP COL" or "HMRC COLS".
Among those eligible for the £300 payment in the coming weeks are those who receive Pension Credit, and the Department for Work and Pensions (DWP) is urging pensioners on low incomes to check their eligibility for the benefit.
Am I eligible for the money?
The money will be added automatically into the account which is used to receive benefit payments
The reference will be DWP COL, along with the claimant's National Insurance number
To qualify for a payment, you must receive one of Universal Credit, Income-based Jobseekers Allowance, Income-related Employment and Support Allowance, Income Support, Working Tax Credit, Child Tax Credit, or Pension Credit
You will need to have been entitled to a payment for one of these benefits between 18 August and 17 September, or payment for an assessment period ending between these dates
Low-income pensioners who are eligible for, but not claiming Pension Credit, can still qualify for the cost-of-living payment if they make a successful backdated Pension Credit application
Those who qualify solely through tax credits will receive their cost-of-living payment between 10 November and 19 November, with the reference HMRC COLS