Two energy firms have been hit with six figures fines for making unlawful marketing calls while falsely claiming to represent other organisations including National Grid and the government.

The Information Commissioner’s Office (ICO) has fined the two companies a total of £250,000 for “bombarding” people and businesses on the UK’s “do not call” register with unlawful marketing calls.

It is against the law for organisations to make marketing calls to anyone signed up with the Telephone Preference Service (TPS) and Corporate Telephone Preference Service (CTPS), which operate a “do not call” register, unless the individual or business has explicitly consented to receive these calls.

An ICO investigation found that Maxen Power Supply, an energy supplier from Ilford, Essex, and Crown Glazing, a green energy firm based in Preston, Lancashire, both made unsolicited marketing calls to people and businesses while falsely claiming to represent other organisations – such as the National Grid, other energy suppliers or the UK Government.

Crown Glazing was hit with a £130,000 fine for making more than 500,000 direct marketing calls to people who had registered with the TPS at least 28 days prior, resulting in 37 complaints.

Meanwhile, Maxen Power Supply has been fined £120,000 after the ICO and TPS received more than 100 complaints about unsolicited marketing calls to businesses and people registered with the TPS and CTPS. Complaints indicated that people were receiving multiple calls on the same day, receiving repeated calls despite requests to opt-out, and were subject to “aggressive” marketing tactics causing potential financial damage.

The complaints also showed that Maxen Power Supply Ltd was making calls from overseas call centres that purported to be from National Grid or the recipient’s existing energy supplier.

The firm claimed that it could help people save money on their energy bills by switching contracts, while asking for information about their current supplier and meter readings.

The company has denied responsibility for the complaints raised, claiming these international call centres were independent contractors and “third party intermediaries.

Andy Curry, ICO head of investigations, said: “Nobody should be made to feel uncomfortable after simply answering the phone.

“People and businesses register with the TPS and CTPS for a clear reason; to stop unwanted marketing calls and protect their privacy. These companies have not only broken the law by failing to check the ‘do not call’ register, but also caused distress and potential financial damage to businesses on the receiving end of their deceptive sales tactics.”

He added: “In the case of Maxen Power Supply Ltd, there is no way of knowing just how many unlawful calls were made due to the use of false company names and ‘spoofed’ caller identities (CLIs).

“This fine should send a clear message that companies cannot avoid the law and avoid detection by the use of third-parties and overseas call centres. The ICO will continue to take action to ensure both the public and UK businesses are protected.”

In addition to the fines, the ICO issued an enforcement notice to both companies ordering them to stop calling people and businesses registered with the TPS and CTPS, or who had previously objected to such calls.