Three of the biggest KiwiSaver providers have scored some of the lowest levels in consumer satisfaction, research has revealed.

Just 36 per cent of ASB customers were very satisfied with the service they were getting while AMP scored 37 per cent and ANZ 41 per cent, according to a survey by Consumer New Zealand.

That compared to an average across 13 providers rated in the research of 48 per cent, which was down from 52 per cent last year.

Sue Chetwin chief executive of Consumer New Zealand, said the fall in ratings was likely to have been influenced by sharemarket volatility which had led to a bumpy ride in the last year.

"But the quality of information consumers got about their funds also affected satisfaction," she said.

The research found three out of four people did not know what they paid in fees each year, two thirds didn't know how their fund compared to the rest of the market and 44 per cent were not confident their KiwiSaver funds would be enough to support them in retirement.

Chetwin said less than half of people (45 per cent) thought their provider did a good job of keeping them up to date with their investment.

Consumers also lacked information about whether their funds were being invested ethically, she added.

"For many, returns are just as important as knowing their money is invested responsibly.

"The majority said they'd be concerned if their cash was being invested in stocks such as gambling, pornography and weapons, but didn't know whether their fund manager excluded investment in these areas."

Chetwin said KiwiSaver providers needed to do better at providing meaningful information about their investment approach.

"Demand for responsible investment is growing rapidly, but KiwiSaver providers aren't meeting this demand," she said.

ANZ which is the largest provider and manages $9.7 billion, was rated below average for keeping customers up to date about their investments.

Craig Mulholland, managing director wealth and private bank at the ANZ, said it put a lot of work into making sure its investors were well informed so they could make an active choice about what fund they were in and achieve their retirement savings goals.

"We've stepped up engagement with investors to ensure they have better information on how their money is invested, the fees they're paying and how their fund is performing.

"The feedback on our work has been positive, but clearly we still have some work to do. It's encouraging to see the emphasis Kiwis continue to place on responsible investment, something we take very seriously."

Meanwhile ASB, the second largest provider which manages $8.5b, scored below average for timely responses to inquiries and its customers were most likely to think comparing KiwiSaver providers was difficult.

Responses about AMP, which manages $5.1b, found a high proportion of AMP customers did not pick the scheme but were allocated to it when they enrolled in KiwiSaver and the customers were the least likely to know which fund type they had.

Milford scored the highest satisfaction rating and its members were most likely to have chosen the scheme independently, chasing higher returns.

The majority had been with the provider for less than five years and three out of 10 had joined in the last year.