The government plans to save money by distributing National Insurance numbers via a letter rather than a plastic card, as part of its drive to reduce the deficit.
It will introduce a new NI number distribution system, replacing plastic cards with letters, in 2011. In the meantime, letters will be sent instead of replacement cards, saving £1m of HMRC money.
The NI number cards are not recognised as forms of ID in the UK, but are simply reminders to the card holders of their NI number.
The plan comes from an idea submitted through the Spending Challenge, a call for members of the public and public sector to send in ideas to save money.
There were over 100,000 ideas submitted to the Spending Challenge website, with 63,000 from public sector workers and the rest from the general public.
"These are the people's ideas," Chancellor George Osborne says. "Over 100,000 suggestions have been put to us and now we're starting to put some of them into practice.
"In doing so, we are directly tapping the experience of those working in the frontline of public services instead of assuming ministers in Whitehall have all the answers.
"No one idea will solve the problems we face, but taken together they can make a real contribution to reducing the deficit and rebalancing the country's economy at a crucial time. People's ideas will have a real impact on the tough decisions ahead."
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