Back when KiwiSaver was set up in 2007 the government appointed six default providers - AMP, AXA, ASB, Mercer, OnePath (part of ANZ), and Tower.
This list has changed over time - AMP purchased AXA, Tower was bought by Fisher Funds, and some new providers were added - so the current default providers are: AMP, ANZ, ASB, BNZ, Fisher Funds, Grosvenor, Kiwi Wealth, Mercer and Westpac.
Some of those names will be familiar to you and some, like Mercer, less so.
Each of the nine default providers runs a default scheme with a conservative investment focus, which means savings in the default schemes are likely to give stable but generally modest returns.
Being in KiwiSaver is voluntary but one of its features is automatic enrolment.
If you start working or change jobs, aren't already a KiwiSaver member and are aged between 18 and 64 you will be automatically enrolled in KiwiSaver.
Inland Revenue begins collecting KiwiSaver contributions from your pay packet and if you don't select a KiwiSaver provider yourself it will then allocate your savings to a default KiwiSaver scheme.
Without being 100 per cent certain, this sounds like what has happened in your case: you have been automatically enrolled with Mercer.
Anyone who doesn't want to be in KiwiSaver has to move fast - there is only an eight-week window after you have been automatically enrolled to opt out.
There is a limited capacity to opt out after that first eight weeks but generally speaking if you didn't want to make any further KiwiSaver contributions and you've missed the opt-out period, your only option would be to take a contributions holiday after you have been a member for 12 months.
If KiwiSaver is for you then you don't have to stick with the default scheme.
You could opt to stay with the same provider but move the savings to a scheme with a different investment focus.
Or you can choose to move to a different scheme at a different provider.
There is a bit of paperwork involved - isn't there always? - but it is still a relatively straightforward process.
Regardless of whether you are in a default KiwiSaver scheme, your provider is required to give you an annual update on your savings, although some providers will do this more regularly and/or provide online access to your KiwiSaver account balance.
I spoke to Mercer directly to ask them what help they can offer you in understanding where your KiwiSaver savings are.
"The first thing is for your reader to get in touch with us and we can talk them through their account and give specific details about their balance," Mercer says.
"The easiest way to do this is to ring our helpline toll-free between 9am and 7pm on 0508 542 578 on any working day.
"They will need to answer a couple of quick questions to confirm their identity and having their IRD number handy when they call is one of the simplest ways to do this.
"At the same time we can provide details of how to access our KiwiSaver website, which gives members access to balance information, webinars, fact sheets, and the ability to update their investment options.
"We can also arrange for a qualifying financial entity adviser to talk to the member about their investment options if they want. Mercer runs KiwiSaver seminars at different times of the year which your reader can attend as well."
To a greater or lesser extent, most KiwiSaver providers will offer information and services along similar lines. To be eligible to withdraw from KiwiSaver you need to be over 65 and have completed five years of membership.
"If your reader meets those criteria they can withdraw all or part of their KiwiSaver account balance," Mercer says.
"While members are not eligible for member tax credits once they reach retirement withdrawal eligibility, they can leave their funds invested in their KiwiSaver account until they need them.
"As well as a full withdrawal, partial withdrawals on a regular or ad hoc basis are also available."
The Inland Revenue Department can also help anyone who thinks they are enrolled in KiwiSaver but is unsure of who their provider is.
Disclaimer: Information provided is stated accurately to the best of the respondent's knowledge at the time of publication. It is general in nature and should not be construed, or relied on, as a recommendation to invest in a particular financial product or class of financial product. Readers should seek independent financial advice specific to their situation before making an investment decision.
To have your KiwiSaver questions answered by the Herald's panel of industry players email Helen Twose, helentwose@gmail com. Sorry, but Helen cannot answer all questions, correspond directly with readers, or give financial advice.