Almost half of GP surgeries have reported clinical documents being lost in the post as they continue to be "swamped" with paper.
A survey of 673 practices shows almost 200 million paper documents are sent in the post every year to GPs at an estimated cost of £1 per letter.
This is despite an "overwhelming majority" (96%) of practices that prefer to receive documents electronically, it is suggested.
Practices claim administration staff spent the equivalent of two working days each week processing documents.
According to the survey, they estimate 18 hours a week could be saved if documents were sent electronically.
"Paper documents are a major irritant for GPs and practice staff," said Dr William Lamb, clinical informatics lead for NHS Cumbria.
"We are operating 19th century communications in the 21st century.
"I am desperate to introduce a complete electronic document system, which will make significant efficiencies in our practice and improve healthcare to our patients."
The survey was conducted on behalf of Healthcare Gateway Ltd, a joint venture by GP software providers INPS and EMIS.