Premium Bond prizes of £1.8million lie unclaimed because winners have died or forgotten about them.
Figures show 64,225 people have each lost out on up to £5,000 in the last five years.
Now bond holders are being urged to check the National Savings & Investments website to see if they’ve won.
The £1,760,689 unclaimed is five per cent of the £35,129,475 scooped since 2013.
In that time there has been a single winner of the top monthly prize of £1million and three £50,000 winners who matched numbers generated randomly by computer Ernie.
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An NS&I spokesman said people could check on nsandi.com, the prize checker app, Amazon Alexa using their Premium Bond holders account number – or by writing to the address on the site.
Winners of £5,000 or more are contacted directly.
Last month saw the first draw using a new Ernie, which generated three million winning numbers in just 12 minutes, compared to the 10 days the original machine took to complete each monthly draw when the bonds were launched as a means of saving in 1956.
However new technology at NS&I – Britain’s largest savings institution – has not always proved better.
In October around 9,000 customers who requested a savings withdrawal online through the call centre faced delays of up to a day because of a glitch.
