Savers will be able to invest a further £10,000 in Premium Bonds from today as the maximum holding limit is being increased from £40,000 to £50,000.
The change follows an announcement in the 2014 Budget that National Savings and Investments (NS&I) would increase the Premium Bonds investment limit.
It comes 12 months after the Premium Bonds limit was increased from £30,000 to £40,000, with a second £1 million prize winner also being introduced from August 2014.
The total amount invested in Premium Bonds has increased from £19.7 billion in 2003 to more than £53 billion.
The total investment value has increased by £6 billion since last June and NS&I expects the total amount will increase again following the increased holding limit from today.
People need to be aged 16 years old or over to buy Premium Bonds - although parents, legal guardians and grandparents can invest on behalf of their child or grandchild.
In addition to the changes to the increased limit, from today, families will be able to buy Premium Bonds for their children directly online or by phone for the first time. Previously, they could only buy by post, or at a Post Office branch.
Instead of paying interest, Premium Bonds are entered into monthly draws for prizes.
Each month, Ernie (which stands for Electronic Random Number Indicator Equipment) - a Blackpool-based random number generator - produces numbers that deliver prizes ranging from £25 up to the £1 million jackpot.
In May, Ernie paid out more than two million prizes, together amounting to over £60 million in value.
Statistically, people living in the South East of England win more often in other regions, because there are more bonds held there compared with the rest of the UK, NS&I said.
NS&I is backed by the Treasury, meaning that money held with it has total security.
Jane Platt, NS&I's chief executive, said: "Last year, we saw a huge level of interest when we raised the limit from £30,000 to £40,000 - and this latest increase to £50,000 is further good news for customers who want save more and to give themselves extra chances to win a tax-free prize."
To celebrate the increase to the allowance and encourage Premium Bonds holders to share their Premium Bond stories - NS&I has launched a new Facebook page - "Premium Bonds made by Ernie".
The Ernie Facebook page can be visited by going to www.facebook.com/PremiumBonds.