Nine out of 10 people do not consider their retirement income when going through a relationship separation later in life, new research shows.

Yet more than half of those surveyed for the Te Ara Ahunga Ora Retirement Commission study said they were worse off financially after separating.

The research, which focused on those aged over the age of 50, found 64 percent of participants felt financially uncomfortable post-separation, compared with 21 percent feeling that way pre-separation.

Women were more affected than men, the study found.

Dr Jo Gamble, research lead for Te Ara Ahunga Ora Retirement Commission told Morning Report one reason those separating later in life reported greater financial instability was because they had less time to "bounce back" in time for retirement.

Another was that some respondents wrongly assumed their KiwiSaver contributions were not part of the relationship property asset pool.

The research showed only 25 percent of people included KiwiSaver when dividing their assets, but 65 percent took bank savings and other investments (including property investments) into account.

"KiwiSaver is actually viewed [by some people] separately; it's viewed as separate property but in actual fact, it's relationship property," Gamble said.

"KiwiSaver is accumulated over time when you're working and earning money and so ... anything that you contribute during your relationship is actually relationship property and needs to be treated as such."

This particularly impacted women, who in many cases still seemed to be the primary caregivers and worked reduced hours or took time out of the workforce altogether, Gamble said.

"Because KiwiSaver is so closely linked to their time spent in the workforce, they end up with much lower KiwiSaver balances."

Another key finding of the research was that 50 percent of respondents just wanted the process of dividing assets to be over, which affected their decision making.

Sixty percent of the men surveyed said their asset division decision making was influenced by a desire for fairness towards both parties, while 44 percent of participants who were influenced by protecting their children psychologically found the outcome of the asset division fairer.

Those who could afford to should get legal or financial advice when going through a separation, Gamble said, and thought should be given to retirement income.

"It's important to consider what's important to you now, but also to consider what's going to be important to you in the future."

-RNZ.