Digital music download service Napster has released pre-pay cards for buying tracks, opening up its store to under-18s without a credit or debit card.
Napster says the cards will open the service to all ages
The cards, which work in a similar way to mobile pre-pay cards, will be on sale in High Street electronics stores.
Rival likes Apple's iTunes and OD2 do not currently offer pre-pay cards.
Tom Dunmore, editor of digital music magazine Rip & Burn, said it may give young illegal downloaders the impetus to switch to legitimate downloading.
"It makes it a lot easier for young people - they are mainly the ones who are illegally downloading - to switch over to legal downloads, " Mr Dunmore told BBC News Online.
"And after the BPI announcement, people need to look for alternatives."
Last week the British Phonographic Industry (BPI) announced it was to sue 28 net users it said were illegally swapping music online.
It warned in March it would take legal action against users of peer-to-peer music services.
The BPI says 15% of file-sharers, which it calls "major uploaders", are responsible for 75% of all illegal music downloading.
Both Napster and the Dixons Group said the cards were an innovation for the music industry and would open up digital downloading to all ages in the UK.
Other services like OD2 - which supplies songs and infrastructure to the likes of MTV, Virgin, HMV and MSN - and Apple's iTunes offer other ways to buy their track online, through gift vouchers and top-up accounts. But OD2 is planning its own pre-paid cards.
"OD2 sees this absolutely as a key area in serving consumers of all ages," said Paul Smith, UK marketing manager.
"OD2 is committed to offering consumers wider and improved payment methods and as such we fully expect to be offering this service through our stores in the near future."
Although iTunes remains the leader in the digital music domain, a report by the US-based NDP Group has shown that the number of legal music downloads across US online services dropped from 1.3 million in April to nearly one million a month.
Mr Dunmore added although the launch of the pre-pay cards was a small step for Napster, it was an interesting move forward for online shopping.
It could bring closer the possibility of combining ways of using your mobile as an electronic wallet, for instance.
"Within a decade, your mobile phone bill will contain a lot of cash purchases," he said. "This sort of thing combines old school physical money and new electronic currency."
In August, Japanese mobile owners became the first to be able to pay with their phones instead of their wallets with a service launched by wireless mobile network NTT DoCoMo.
The Felica system lets those with compatible mobile handsets get cash and carry out other secure credit card-based transactions using a 3G network.
Motorola and MasterCard are also currently testing mobiles that can carry out secure financial transactions.