The campaign, designed by Target Direct, involves 3 million mail packs, 10 million inserts in 35 magazine titles, 13 television channels, 5 national newspapers and 7 web sites. There is also a major door-to-door programme.
The charity has invested £2.5 million in the recruitment component of the campaign and hopes to raise £7.8 million in cash gifts from 240,000 new supporters.
Regular donors will be asked to help the Salvation Army raise an additional £4.8 million to support its regular social programmes and services.
Christmas is the charity's most important fundraising opportunity but this year is particularly vital. Two months ago the Salvation Army's major Bill Cochrane warned that the charity's drop in income over the past three years threatened the continued existence of some of the organisation's relief programmes.
Julius Wolff-Ingrams, director of marketing and fundraising at the Salvation Army, said it is "crucial" that the Christmas appeal reaches its £12 million target.
"We're facing an increasingly competitive marketplace," said Wolff-Ingrams.
"This year it's vital that we successfully reach new audiences by communicating different aspects of our work."
The creative has been designed to target new and younger donors. One mailshot, titled Love on the Frontline, talks about the Salvation Army's work in reducing youth crime and focuses on its efforts with young homeless people.
The organisation is also stepping up its use of online media with advertising on lifestyle web sites and portals which direct people through to a new fundraising section on the charity's main web site, www.salvationarmy.org.uk.