The organisation has launched a national campaign to target companies that try to convince their customers to switch to much cheaper paperless e-billing on the basis of unsupported environmental claims.
Martyn Eustace, Two Sides director, said:"If organisations want to encourage customers to switch to e-billing because they believe it offers efficiency then we have no quarrel with that, but we will fight all the way to stop them from making a link between reducing the use of paper and helping the environment unless they have proof that this is so."
He added that the connection made between reducing the use of paper and helping the environment created "a misleading impression" of the sustainability of print and paper and was "unsupported by facts" and so contravene the latest Committee for Advertising Practice code.
Two Sides accused a raft of major high street banks, including Lloyds TSB, Nationwide, NatWest, RBS and Santander, of making statements connecting e-billing or other electronic services with being better for the environment.
In the telecoms sector, O2 UK, Orange, Talk Talk, T-Mobile UK, Virgin Media and Vodafone UK were all picked out, while in the utilities sector, Two Sides highlighted a total of 14 companies, including Eon Energy, Scottish Power, Southern Electric, Swalec, South East Water and Southern Water.
According to Two Sides research, 43% of the financial institutions, 70% of the telecoms providers and 30% of the utilities companies surveyed included unsubstantiated claims connecting paperless communications with a reduced environmental impact.
Eustace claimed that these major UK corporations were "flouting advertising regulations and risk reporting to the Advertising Standards Authority (ASA)".
He said Two Sides will be writing to the many companies that are in breach of advertising regulations and, if these concerns are not addressed, it will lodge a complaint with the ASA.
Eustace added: "Paper is a renewable and recyclable product that, if responsibly produced and consumed, is an environmentally sustainable media and may be the sustainable way to communicate.
"The forestry and paper industries are major guardians of this precious and growing resource."
According to Two Sides research, the following banks, building societies, telecoms and utilities companies connect e-billing or other electronic services with being better for the environment.
Financial institutions: American Express UK, Anglo Irish Bank Group, Bank of Scotland, Barclaycard, Halifax, HSBC, Lloyds TSB, MBNA, Nationwide, Natwest, Royal Bank of Scotland, Santander.
Telecoms: Kingston Communications, O2 UK, Orange, Sky, Talk Talk, Virgin Media, Vodafone UK.
Utilities: MyBillsOnline, Atlantic Electric & Gas, Eon Energy, Scottish Power, Scottish Hydro, Southern Electric, Swalec, Anglian Water, Bournemouth & West Hampshire Water, Essex & Suffolk Water, South East Water, South Staffordshire Water, Southern Water, Sutton and East Surrey Water.
