As the November draw looms, Britons are being reminded how to check if they’ve won a prize as interest rates have risen. October’s prize fund rate increased from 1.40 percent to 2.20 percent which NS&I states is the ‘single biggest increase’ in more than 40 years.The move made the odds of winning increase from 24,500 to one to 24,000 to one.The change also increased the number of people able to win the £100,000 cash prize from 10 in September to 18 this month.Meanwhile, the number of £50,000 prizes increased from 20 to 35.There were also 19 times as many £50 and £100 prizes paid out in October.READ MORE: Millions of pensioners may be missing out on DWP benefit worth £4,800 a year NS&I has increased interest rates to 2.2 percent (Image: GETTY)NS&I awarded £218million worth of prizes in this month’s prize draw – up £4.9million on previous months due to the prize rate increase.NS&I urges Britons to check if they have won a prize. Usually, prize winners are notified if they win, however, sometimes NS&I cannot contact the winner.This is due to people moving or changing their contact details without letting NS&I know and can lead to unclaimed prizes.People can check if they have won by heading to NS&I’s website or by checking the prize checker app.DON’T MISSMortgage warning as 850,000 could see rate rises after base rate decision next week [INSIGHT]Woman shares ‘little changes’ she made when shopping to help her ‘save thousands’ [ANALYSIS]The help available from energy suppliers if you can’t pay bills – from British Gas to Ovo [UPDATE] Each month, two Premium Bond holders have the chance to become a millionaire (Image: EXPRESS)Ian Ackerley, the NS&I’s chief executive, outlined why they chose to raise rates in this way.Mr Ackerley said: ‘Today’s increases across our variable and fixed-rate products mean that our customers get a welcome boost to their savings.’The changes come in the same month that we increased the Premium Bonds prize fund rate.’Some of the rates we’re now paying – including on Premium Bonds – are the highest that they have been in over a decade, which is great news for savers.’The changes to interest rates we’ve announced today will help ensure that our products are priced appropriately when compared to those offered by our competitors.’