A charities group has called on solicitors to remind clients to consider leaving money to good causes in their will, after a trial scheme increased legacies left by £1m.

Three times as many Britons would leave a gift to charities that they are passionate about in their will, if their solicitor reminded them to consider it, the trial results suggested.

The six-month project, which looked at 1,000 new wills, was conducted by the Cabinet Office behavioural insights team, in partnership with charity Remember A Charity and the Co-operative Legal Services (CLS).

It showed that when solicitors told clients that leaving a gift to charity was an option, the percentage who did so rose from 5 to 10%.

When clients were asked if there were any charities that they were passionate about, giving rose again to 15%.

During the trial an additional £1m of gifts was left to charities in wills.

In 2012 CLS instigated an ‘always mention’ policy, under which all will-writing customers were prompted to consider including a charity in their will.

The trial compared data from customers prior to the instigation of the policy with two groups.

Clients in the first group were asked ‘have you considered leaving any money to charity in your will?’ and those in the second group were told ‘many of our customers choose to leave money to charity in their will – are there any causes you’re passionate about?’

Director of Remember A Charity, Rob Cope, said the increase is due to the fact that significant numbers of people support the idea of leaving a gift to charity but few remember to do so when it comes to writing their will.

He said: ‘Our latest consumer research shows that nearly half of people have thought about leaving money to charity in their wills but only around 7% of people currently leave a gift, that’s a big gap.

He added. ‘The trial shows that if solicitors simply ask people to consider leaving a gift then this gap closes significantly.’ Cope called on all solicitors to remind their clients to consider leaving a gift to charity in their will.

He said that gifts in wills bring in £2bn a year for UK charities - 13% of all charitable donations. ‘A trebling in the number of people leaving a gift could have a significant financial impact for good causes.’

CLS director Christina Blacklaws noted the results demonstrated the impact that a simple reminder can have to increase the income of good causes.

Minister for civil society Nick Hurd said: ‘We are working with partners to see how we can make it easier and more compelling to give. He concluded: ‘This study shows how generous people are prepared to be, if asked in the right way.’