Carers UK has formed a partnership with British Gas and Scottish Gas to use energy bills to inform carers about the help available to them.
Under the scheme, which is being piloted in Scotland and the North East, gas and electricity bills will include a message encouraging customers who look after someone to call a helpline number.
A spokesman for the charity said the venture was aimed at people who didn't recognise themselves as carers and therefore weren't aware of the benefits available. Those who look after relatives, partners or friends for a certain number of hours can be eligible for concessions but don't often claim them.
The idea was proposed by Carers' president Roy Gardner, who is also chief executive of Centrica, the company which owns British Gas and Scottish Gas.
Carers said this would be the first time that bills have been used to promote charitable purposes.