By Paul Lewis BBC Radio 4's Money Box

Minister for Pensions Reform, Mike O'Brien, is looking into procedures

The government has admitted its helpline has been giving the wrong information about state pensions to some married women.

Minister Mike O'Brien told the BBC that he had changed procedures to improve the advice given.

He admitted the rules about women paying backdated National Insurance contributions were "complex".

And he said he was reviewing how to make it easier for women to pay extra contributions to improve their pension.

Up to half a million women who currently get no state pension, could get one, if they paid a few years backdated national insurance contributions.

But complex rules govern who can pay the contributions and how many years they can backdate.

After this was explained on Radio 4's Money Box programme, many listeners who contacted the Department for Work and Pensions helpline were told they could not pay the contributions.

Erroneous advice

We are trying to... make sure our procedures reduce the likelihood of those errors happening Minister for Pensions Reform, Mike O'Brien

But Minister for Pensions Reform, Mike O'Brien, now admits:

"Some people did get advice, which I understand, may well not have been the right advice, therefore what we need to do is find ways of making sure our staff do give the right advice."

He said procedures were being changed so that helpline staff would take details, check the facts, and then call people back.

But he warned that because the rules were so complex, "I do not want to say to you there will never be a mistake.

"What we are trying to do is make sure our procedures reduce the likelihood of those errors happening."

Possible rule change

MORE INFORMATION HMRC National Insurance Deficiency Helpline: 0845 915 5996 (Monday to Friday 8am - 8pm and Saturday 8am - 4pm) General National Insurance Enquiries for individuals: 0845 302 1479 (Monday to Friday 8am - 5pm) The Pension Service: 0845 606 0265 or for Welsh speaking customers: 0845 60 60 275 (Mon to Fri 8am - 8pm) The Pensions Advisory Service helpline: 0845 6012923 (9am to 5pm, Monday to Friday, 9am - 5pm) HM Revenue & Customs HMRC leaflet

He pointed out that women who reached pension age from 6 April 2010 would qualify far more easily for a pension, with only 30 years' contributions instead of the current requirement for 39 years.

But he was looking at changing the rules to make it easier for women who retired before, what he called "the cliff edge" date, to qualify.

"We are trying to find ways within reasonable cost, so that we are able to help women who have a broken work record, to ensure they do get a better pension.

"It is enormously expensive but... we are in discussions with the Treasury on how we could allow some of the women... to pay voluntary contributions outside the current arrangements, and therefore improve their pension."