KiwiSaver members are switching providers in increasing numbers, but how can you know whether it's the right thing to do?

There were 21,757 transfers between KiwiSaver providers in June, up from 17,556 in May and 14,089 in April.

A year earlier, 13,866 people transferred.

Providers said it was probably because people were taking a more active interest in their investments, and new options have become available in the market.

Sharesies, for example, has added more than 30,000 members since it launched.

Strong sharemarkets have also meant many funds have delivered strong returns.

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Pie Funds chief executive Ana-Marie Lockyer said there was more engagement with KiwiSaver generally, which seemed to be contributing to an increase in switches as people thought about whether they were in the right fund for their goals.

"At Pie, we've also seen an increase in transfers to us since entering the adviser market. More people are seeking financial advice as their KiwiSaver balances grow, and advisers are playing an increasingly important role in helping members assess whether their current provider, fund and risk profile are the right fit for their circumstances and goals. "

Kernel founder Dean Anderson agreed people were paying more attention.

He said Kernel had received 10 percent or 11 percent of switching activity over the previous quarter.

Milford head of KiwiSaver Murray Harris said it had seen people moving into higher-risk funds, such as from growth to aggressive and balanced to growth.

"That would signal that continued strong markets are encouraging members to take on more risk. That would also align with KiwiSaver being a long-term investment so members choosing higher growth fund options. We continue to see very strong transfers in from other providers, and a very small number of transfers out to some of the thematic ETF funds."

How do you know if moving is the right thing to do?

There are a few things you could consider.

After-fees returns: When you're comparing the returns that funds have been achieving, it is usually best to look over a longer time period, such as a number of years. This means you're less likely to be distracted by short-term blips. You can look at performance with tools such as those available at Sorted, or consider Morningstar data. Past returns are no guarantee of what you'll get in the future but if you compare funds with others that have a similar investment strategy - such as growth funds compared to other growth funds - you may get a sense of how they are performing.

Fees: While returns can vary depending on what markets are doing, fees are much easier to predict. KiwiSaver fees range from anything from 0.2 percent to more than 2 percent. Paying more isn't necessarily bad as long as you're happy with what you're getting for your money.

Investment style: Do you want an active manager who's making decisions about where your money is going, or are you happy to ride the market? Do you want exposure to a particular industry or sector, or to avoid something? These sorts of questions may guide you to particular managers who might share your worldview.

Other factors: Do you want personalised financial advice? Do you like seeing your balance alongside your online banking or does it just cause stress?

"For anyone considering a move, they should be thinking about whether their KiwiSaver fund matches their investment timeframe and tolerance for risk, whether they understand and have confidence in their provider's investment approach, and whether they're getting the level of service and advice they need," Lockyer said.

"KiwiSaver is a long-term investment, so any decision to switch should leave members feeling confident they're in a solution that's right for them over the long term."