Four million work from home - TUC
More than four million people now work from home after a huge increase in recent years, according to a study.
The TUC said the number of regular home-workers had risen by more than half a million since 2007 and by 62,000 over the past year.
The biggest boom has been in the South East, up by 132,000 since 2007, while the South West has the highest proportion of people working from home at one in six.
Demands from staff for more flexible working and changes in technology have fuelled the trend, although the growth might be starting to tail off, said the union organisation.
The report, to mark national work from home day, said many employers were still afraid to allow staff to work away from the office.
TUC general secretary Frances O'Grady said: "Cheaper and quicker internet access has played a big factor in the growth of home-working in recent years.
"Modern home-working is good for the economy as it increases productivity, helps businesses hold on to talented staff, and allows people with caring responsibilities or a disability to access the labour market.
"Despite all these benefits, many employers still don't trust their staff to work from home and force them to make unnecessary, time-consuming trips into the office so they can keep an eye on them. Employers need to take a more enlightened approach to home-working as it can benefit business, the workforce and the wider economy."
Phil Flaxton, chief executive of Work Wise UK, which campaigns for flexible working, said: "Stronger economic growth has clearly boosted the number of people in work, but it has not yet boosted productivity, which is the real key to long-term prosperity in our very competitive world.
"To help achieve the productivity improvements necessary, many employers need to change their outdated attitudes to home-working and embrace new ways of working in the 21st century."
Northern Ireland is the only region of the UK where the number of home workers has fallen since the recession, the research showed.
The TUC added that around 650,000 people with a disability work from home.