The biggest income discrepancy was between men and women with 16-20 years experience. On average women within this category were paid 25 per cent less.
This cannot be attributed to a lack of experience.
Women with more than 21 years were paid 23 per cent less. Compared to women with less than 5-years experience, or graduates, who were paid 9 per cent less.
Abbott said there are many reasons for this, including fewer women in high-powered roles.
"We know women are paid less in those roles, and there are fewer in these roles also."
A prominent New Zealand accounting firm's HR manager said there is no gender inequality within the firm.
"Income is based on what you do and produce, not on your gender."
However, she said pay gaps were common across many industries in New Zealand.
At another firm, another HR manager said:
"It's not just in accounting, it's in marketing, sales and human resources too. The glass ceiling is wide-spread in this organisation."
Abbott said NZCIA has shared these results with the Human Rights Commission, which will profile the issue in this year's census of woman's participation.
The report, released every two years, monitors the equality of women's pay and seniority within a variety of industries.