Under little-known rules, companies that fail to register their energy usage by 30 September will be hit with fines that could reach £45,000.

The Carbon Reduction Commitment (CRC) is requesting that businesses declare their energy usage, with potential charges for every ton of greenhouse gases produced. These payments are expected to average £38,000 a year for medium-sized firms and up to £100,000 for larger organisations. Surveys have shown that thousands of businesses are unaware they are supposed to be taking part, or even that the scheme exists at all.

Under the scheme, any company or public sector organisation that consumes more than 6,000 megawatt hours (MWh) of energy a year – meaning a power bill of about £500,000 – must register its energy use by the end of next month. From April, firms will need to buy permits for each tonne of carbon dioxide emitted. For those using 6,000MWh, that could mean £38,000.

The scheme is intended to create a financial incentive to cut energy use, and those organisations that record the biggest reductions will get bonuses, funded by penalties imposed on those with the worst record.

Of about 4,000 organisations estimated to qualify for the scheme, only 1,229 have registered to date, leaving thousands at risk of fines. Missing the deadline will mean an immediate £5,000 fine and £500 for each day after that, up to a maximum of £45,000.

Another 15,000 smaller organisations are also required to register and could be expected to buy permits in the future. If they miss the September deadline, they face fines of £500.

With a double-dip recession on the cards, these fines will put even more pressure on already stretched businesses.

For more information, visit the Carbon Trusts website