Energy suppliers National Grid face an £8 million fine after the company breached regulations on providing accurate information to the energy industry regulator.
Watchdog Ofgem announced its intention to fine the energy supplier after the firm failed to pass on correct information during the reporting period 2005-6 to 2007-8.
The regulator said the proposed penalty would have been higher if it were not for the "co-operation and corrective action" by National Grid Gas.
Ofgem chair Lord Mogg commented: "Ofgem's work to ensure consumers receive value for money for network investment and replacement relies heavily on receiving accurate reporting from companies.
"Ofgem's actions today reinforce our strong message to all energy companies that misreporting cannot and will not be tolerated."
The watchdog noted that the cheap energy company did not benefit financially from the misreporting and pointed out that any consumer detriment has already been addressed.
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