"Suppliers must consider a customer's vulnerability and ability to pay to a closer degree, particularly with what is likely to be a very challenging winter for many," Cathryn Scott, a director at Ofgem, said in a statement.

Ofgem said the failings related to a lack of support for vulnerable customers in the case of Utilita and debt repayment plans at Scottish Power, a subsidiary of Spain's Iberdrola.

"The rise in cost of living is an increasingly important public issue, and we expect urgent and immediate action on the points raised," Scott said.

The companies must now change certain practices and deliver independent audit reports to Ofgem by Oct. 31.

The two provisional orders come ahead of the findings of a full market review into how suppliers make sure they are supporting customers struggling with bills, due to be published by Ofgem shortly, the regulator said.

(Reporting by Nora Buli in Oslo; editing by Jason Neely)