The report, from Ofgem, comes as the market recovers from a string of small utility firm collapses.
Just 73 per cent of people in Scotland the the UK as a whole said they were happy with their supplier - a higher proportion of unhappy customers than the previous two quarters and a fall from 77 per cent north of the border in the final quarter of 2018.
Peter Earl, head of energy at comparethemarket.com, said: “A slight fall in the number of customers satisfied with their energy provider – part of a longer term decline - could be down to a high number of supplier collapses, 12 and counting in the last year.
“Even with measures in place to protect consumers from a supplier failure, customers are still moved from one supplier to another, which fuels further confusion in an already complex energy market.”
The report found that satisfaction with customer service is higher among the digitally excluded, vs those who were online, those with a smart meter and customers paying by direct debit.
A total of 79 per cent of people who were unhappy cited bill problems as the main reason for their dissatisfaction.