From Thursday onwards, customers with pre-payment meters who are unable to add credit can approach their suppliers to discuss other options to maintain power. That has the potential to benefit over 4 million households.
Disconnection of credit meters will be completely suspended, while energy customers in financial distress can also ask their suppliers for debt repayments and bill payments to be reassessed, reduced or paused, the government said.
The agreement has been signed by all UK domestic energy suppliers and will come into force immediately.
Britain's biggest energy suppliers, including Centrica's British Gas, SSE, EDF's EDF Energy, Iberdrola Scottish Power, control around 70% of the retail energy market.
There are also around 50 smaller suppliers, including Bulb and Octopus Energy.
"Today those most in need can rest assured that a secure supply of energy will continue to flow into their homes during this difficult time," UK Secretary of State for Business and Energy Alok Sharma said.
On Wednesday Britain's National Grid said it had plans in place to keep the lights on throughout the coronavirus outbreak as more people than usual remain at home.
The chief executive of Energy Networks Association, David Smith, said Britain's electricity and gas network is reliable, and more than 36,000 employees are working to continue to provide a safe and reliable supply of energy.
By Nina Chestney