Heating your home to a cosy temperature in winter can be expensive. The Warm Home Discount can help pensioners and low-income households save £140 on their energy bills - but as many as 1.4m stand to miss out, according to analysis from Compare the Market.
The analysis says 1.3 million pensioners are failing to claim pension credit - a requirement for the saving to be applied automatically. Plus, an estimated 100,000 eligible over-65-year-olds might be locked out because their energy supplier isn't signed up to the scheme.
This comes even as more smaller energy suppliers are required to offer the discount this year.
Here we explain what the Warm Home Discount is, how to claim it and where else to find help paying your energy bills over the colder months.
The Warm Home Discount was launched in April 2011 to help vulnerable households struggling with their winter energy bills.
If you're eligible, you'll get a one-off £140 discount on your electricity or gas bill to help cope with the extra cost of heating your home over the colder months.
The money isn't paid directly to you. Instead, it's a discount that is credited to your energy account, prepayment card or key between October and March.
The Warm Home Discount is available to households that fall into one of two groups: the core group or the broader group.
The broader group applies to energy customers who are on a low income or qualify for certain means-tested benefits.
You should get a letter by 6 December confirming your eligibility or telling you how to apply. If you need to provide further information, you'll have to send it by 28 February 2020 to ensure you receive the payment for the year.
If you qualify for the broader group, you need to apply for the Warm Home discount through your energy provider. You should check with your supplier to see if you meet its eligibility criteria.
Bear in mind that only firms with 200,000 customers or more have to participate in the Warm Home Discount scheme this year, which means some smaller suppliers are exempt. That said, smaller suppliers could be cheaper for you overall, even when taking the discount into account. So it's worth checking whether you will be better off switching.
All Warm Home Discount payments should be received by the end of March 2020.
In the past, only bigger energy suppliers, those with 250,000 or more customers, had to guarantee eligible customers will get the winter payment.
But this winter, energy suppliers that have more than 200,000 domestic customers are required to offer the discount, which means some smaller firms have to take part.
By 2020-21, all those with at least 150,000 customers must participate.
The changes only apply to the core group. So, in total, 30,000 extra pensioners are expected to get the payment by 2021. But overall the number of low-income households and those in vulnerable situations benefiting from the rebate will not increase.
If you're finding it difficult to cover your energy bill this winter, there is other help available.
The government has a range of home grants that can help you pay your bill in the winter months.
The Winter Fuel Payment is a tax-free payment from the government which is available to help older people during the winter months.
The amount you get depends on your circumstances, including how many people live in your household, if you live in a later life care facility and if you receive any benefits.
The Cold Weather Payment is made to households in receipt of benefits to pay for the extra cost of energy during very cold weather.
To qualify, the average temperature where you live must fall or be forecast to fall to 0°C or below for seven consecutive days between 1 November and 31 March each year.