If you have a prepayment meter and are self isolating, ring your supplier and they will send you 2 weeks’ worth of gas/electricity or if you have a smart meter they will top you up.
British Gas 0333 202 9802
EDF 0333 200 5100
EON 0345 052 0000
npower 0800 073 3000
Scottish Power 0800 027 0072
SSE 0345 026 2658