A new report shows one in seven women in a relationship will experience economic abuse.
This occurs when a partner controls a woman's finances, restricts their access to money, or sabotages their ability to earn an income.
The most common act, reported by 8.8 percent of women, was their partner refusing to provide money for household expenses.
The study of more than 1000 women by the University of Auckland found this can compound the effects of other forms of abuse.
Women who experienced economic abuse on top of other forms of physical, sexual or psychological violence by a partner were almost five times more likely to be diagnosed with a mental health condition, and almost five times more likely to lack regular access to food.
Women who reported economic abuse were also almost three times more likely to be receiving a benefit.
The study's lead author, Professor Janet Fanslow of the university's School of Population Health, said when economic abuse was added into the picture, it really increased the "devastating consequences for women".
"Intimate partner violence tends to be a whole pattern of different types of abusive behaviour," she said.
The researchers looked particularly at women in this study, because the pattern of abusive behaviour and control that women experience from men is really different from what men experience.
"We're not seeing the same things for men," Fanslow said.
A common impact of financial abuse was that it made it more difficult for women to leave a relationship.
Therefore, Fanslow said it was crucial for women's support organisations to conduct assessments which considered not only physical and sexual violence, but economic abuse and other controlling behaviours too.
From a legal perspective, recognising economic abuse as part of coercive control was essential.
On a broader level, it raised questions about gender equality, including economic disparities such as the gender pay gap, which could impact a woman's ability to leave and stay out of violent relationships.