Hundreds of thousands of savers have waited months to receive interest and cash prizes, according to Money Saving Expert.
It comes after a glitch following a system update.
The issue impacts more than 300,000 National Savings & Investments (NS&I) savers – with funds worth more than £1bn.
There are also almost 1,000 Premium Bond prizes affected, worth £27,175 in total.
Anyone who saves with NS&I is urged to check now for any owed interest.
MSE says : “Some savers who deposited money into their Direct ISA, Direct Saver, Income Bonds, Investment Account or Junior ISA accounts between July 19 and and September 29 2021 may have waited up to six months for missing interest payments.”
NS&I said affected customers with Direct ISAs, Direct Savers, Investment Accounts and Junior ISAs have had their accounts automatically updated with any interest payments backdated in January this year.
Income Bond customers have also automatically had any interest that was due paid as part of either their January or February dividend payment.
However, if you think you’re affected and have not had your interest paid, you can contact NS&I either by phone or via its online web chat.
Savers who purchased Premium Bonds at the end of July, August and September last year may also be missing prize wins.
NS&I said it is able to check affected Bond numbers against the winning prize numbers, meaning you won’t miss out on any wins.
It will notify affected prize winners in writing and missing prizes will be paid via their chosen prize payment method.
Those who automatically reinvested prize wins into more Premium Bonds are not affected.
On the missing interest payments, an NS&I spokesperson said: “Following an update to NS&I’s systems in mid-July, it was discovered that – when customers were investing in NS&I products – the incorrect date for the sale was being applied to the transaction in some cases. NS&I apologises to all customers affected.”
With regards to missing Premium Bond prizes, NS&I added: “Retrospective prize checks have been run on the affected Bonds, and customers will be notified in writing by NS&I of any prize wins.”
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