full-year profits hit £3.3bn for 2022, more than triple the £948m it made the year before.
Centrica said it would extend its share buyback scheme, the money it returns to its shareholders, to £300m and also pay out a full-year dividend of 3p a share.
Unite general secretary Sharon Graham said Centrica had been "coining it in from our massive energy bills while sending bailiffs to prey on vulnerable consumers the length and breadth of the country".
TUC general secretary Paul Nowak said that the British energy market was "broken" and called for energy retail companies to be brought into public ownership.
Simon Francis, coordinator of the End Fuel Poverty Coalition, added the energy market was "failing consumers and is in desperate need of reform".