Private finance companies often had high interest rates and penalties for non-payment which could increase the price of goods and took longer to pay off.
Advance payments were taken directly from a benefit so beneficiaries didn't need to worry if they didn't have available funds that week to meet payments, he said.
Mr Overbye said many advances were for things which others took for granted such as a big power bill or clothing.
"It would be great if people did not have to go into debt for these essential things, however that is not always the reality for many of our clients."
Mr Overbye said people should see if they could find goods such as beds and lounge suites secondhand. Some secondhand stores had arrangements with Work and Income for repayments.
The number of grants has risen slightly each year. Beneficiaries in the Bay of Plenty region had 23,914 grants approved in 2014 and 22,704 in 2013, according to the Ministry.
To qualify for the advance payment, a client needed to have an immediate and essential need, meet hardship obligations including budgeting, meet an income and asset test and buy goods or services from a preferred supplier if an arrangement was in place.
Bay of Plenty beneficiaries had 3064 applications for advance payments declined last year.
Reasons for having an application declined included "need can be met in another way", "not an economic purchase" and "not an emergency situation".
Nationwide beneficiaries received 313,334 grants worth $127,756,265 last year. They had a further 18,187 requests declined.
Auckland Action Against Poverty co-ordinator Alastair Russell said significant numbers of people were unaware they were eligible for advances.
While the group was Auckland-focused, it was happy to talk to beneficiary groups and community groups elsewhere.