The Federation of Family Budgeting Services says it's had 16% more inquiries this year, with a surge in salary and wage earners seeking help.
This sector of society now makes up almost a third of the agency's clients.
Chief executive Raewyn Fox says its clients have $48 million in overdue debt and their total debt is more than $234 million.
The agency has fielded more than 293,000 inquiries.
Ms Fox says many families are struggling to cover basic food costs such as bread, milk and cheese. Rising mortgage costs are a major factor affecting middle-income earners.
The Auckland City Mission is experiencing a similar trend, with more salary and wage earners asking for food parcels.