UK - Public sector pensioners who have been underpaid their benefits due to administrative errors dating back to 1978 will receive full arrears, the government has confirmed.
Liberal Democrat treasury spokesman Vince Cable alerted MPs to the problem and cabinet office minister Liam Byrne confirmed the error - which dates back to 1978 - in December.
It has now emerged that a number of the affected pensioners were underpaid due to the same error.
The government could not confirm the number of people affected but promised to rectify the situation.
A cabinet office spokesman said: "Before Christmas, the government discovered a problem which affected several public service pension schemes which has resulted in a significant number of individuals being overpaid.
"The government decided not to recover overpayments but to correct the pensions in payment from April 1, 2009.
"In cases where pensions are underpaid, those affected will receive the arrears in full."
The government is in talks with the UK and Irish pensions regulators over how to protect members of cross-border schemes in the event of a no-deal Brexit.
The equalisation of guaranteed minimum pensions (GMPs) is at least two years away from being completed, and could take longer than four years for some schemes, a poll has found.
The Pensions Regulator will consider if schemes should be required to have professional trustees and assess the case for greater regulation of administrators and system providers, PP can reveal.
UK inflation fell from 2.3% to 2.1% in December, approaching its lowest rate for two years, according to the Office for National Statistics (ONS).