In the three years since the launch of MyLostAccount, the financial industry scheme which helps account holders find lost accounts, it has conducted more than 400,000 searches and reunited people with more than £475 milliion in forgotten savings.
But there are still millions of pounds sitting in lost accounts waiting to be reclaimed. And it's not just bank and building society accounts which get forgotten about.
NS&I has just launched a nationwide search to track down the winners of over 740,000 unclaimed Premium Bond prizes which include one prize worth £100,000, one prize worth £50,000 and four £25,000.
Jill Waters, NS&I's operations manager, said: "It is likely that the winner of the £100,000 prize is unaware or has forgotten that they have Premium Bonds - the lucky winner has just £25 invested.
Prizes often become unclaimed as a result of people moving house, or forgetting that Bonds have been bought for them as a child, or executors are unaware the Bonds are held when someone dies."
While it might be difficult to keep track of all your accounts and savings, it's vital that you do so if you want to earn as much interest as possible - especially in these difficult times.
Here, we look at how to find any lost savings, and how to ensure all your money is working as hard as it can for you.
How to track down lost savings
If you think you might have money in a lost account, or could be a Premium Bond winner, then have a hunt around for any paperwork which might help reunite you with your cash.
If you have your Premium Bond holder's number, then all you have to do is enter it on the NS&I website and you'll find out whether you have any unclaimed prizes.
For those with forgotten bank or building society accounts or NS&I savings accounts, you could try the tracing scheme at MyLostAccount - the free service from the British Bankers' Association, the Building Societies Association and National Savings and Investments (NS&I).
Once you make a claim through the site, a response will be given within three months of your completed claim form being received. In the case of NS&I, you should receive a response within one month.
As soon as you've located any forgotten savings, you need to decide where to move them to so they can earn the maximum interest possible.

Where to earn the best returns
Despite the Bank of England base rate still being at 0.50%, it is possible to earn competitive rates of interest, especially if you are prepared to tie up your savings for a while.
For example, Allied Irish Bank's 1 Year Fixed Rate Bond pays 3.40% annual interest before tax to savers with £1,000 or more to invest and who won't need access to their money for a year.
If you're after even higher rates, then Cahoot's 2 Year Fixed Rate Bond Issue 4 pays a generous 4.01% annual interest a year if you can afford to leave your money untouched for two years.
However, you do need a steep minimum deposit of £25,000 to qualify for this rate, so it won't suit savers with smaller sums to invest.
An alternative account that may be worth considering is Bank of Ireland's UK Web Bond Issue 4, which pays 3.90% and can be opened with a minimum investment of £500.
Again, you cannot make any withdrawals during the account's two-year term. The best rates go to those who can lock up their money for five years.
Kent Reliance Building Society, for example, pays 4.70% on its five-year fixed rate bond, which can be opened with £1,000, while Scottish Widows pays 4.60% annual interest before tax on a minimum investment of £10,000 held in its 5 Year Fixed Rate Term account.
However bear in mind that while these returns might look generous now, they may not seem quite as appealing in a few years' time when interest rates start to rise.
Top easy access accounts
Savers who'd rather have easy access to their money can still find some impressive rates of interest.
The current market-leading easy access account is Coventry Building Society's Poppy Online Saver account, which pays an impressive 3.15% annual interest before tax on a minimum investment of just £1.
The rate includes a 1.15% bonus for the first 12 months, so you may want to move your money when this disappears. You can make up to four no notice penalty-free withdrawals from this account each year.
Alternatively, Nationwide's MySave Online Plus account pays 3.12%, but you can only make one penalty-free withdrawal a year from this account.
This rate includes a bonus of 1.58% which is only payable for the first year, so you may want to move your money at the end of this period.
Don't forget ISAs...
One of the best ways to maximise the amount of interest you earn is by making sure you use your annual individual savings account (ISA) allowance each year. This tax year you can invest £5,340 in a cash ISA tax-free.
Nationwide Building Society's Online ISA currently pays the market-leading rate for easy access ISAs at 3.10% but you only qualify for this rate if you have at least £25,000 or more to invest.
Savers who pay in the minimum £1,000 permitted to open the account earn a much lower rate of 2.75%. If you don't have as much as £25,000 to put away, then a better option is Northern Rock's Online eISA.
This account, which is exclusive to MoneySupermarket.com, pays 3.05% annual interest tax free and can be opened with a minimum investment of £1.
Please note: Any rates or deals mentioned in this article were available at the time of writing. Click on a highlighted product and apply direct.
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