Kiwis are putting more on their credit card than ever before, raising concerns about how quickly that debt will be paid back.

Reserve Bank figures show Kiwis spent $3.9 billion in December alone - a new high for monthly credit card billings which typically peak at Christmas time.

The December figure was $162 million higher than the previous December and seasonally adjusted was an increase of 8.4 per cent.

Daniel Snowden, an economist with the ASB Bank, said part of the increase could be attributed to population growth, inflation and the type of things people were spending their money on but even taking those into account the growth was strong.


Inflation was up 1.3 per cent last year while the population grew by 0.87 per cent.

Snowden said the spend-up probably reflected the country's strong economic growth and the fact people were feeling confident.

"People are going out confident and happy to spend."

He said others may be choosing to put all of their purchases through a credit card to take advantages of reward offers like cash backs and airpoints that had recently been on offer.

"It's a combination of all those things adding up."

Liz Koh, a financial adviser at Money Max, said she suspected people were taking a more relaxed approach to spending because of their optimism about the future.

"When people are confident about their current and future financial situation they are inclined to take on more debt, as they are sure they will be able to repay it."

But she said this was not a good trend.

"Eventually the tide will turn, as it always does, and those with high levels of debt may struggle."


David Boyle, group manager of investor education at the Commission for Financial Capability, said it was fine to give the credit card a good thrashing the key was to make sure you paid back the money quickly.

"How quickly does that increase get reduced? My fear is if it doesn't go down that is when it will have a massive impact on people's day to day lives."

Kiwis don't have a good track record when it comes to paying off our credit card balances in full.

Last year New Zealanders paid interest on around 63 per cent of their outstanding credit card debt and the average interest rate on outstanding balances was 18 per cent.

Canstar released figures earlier this month estimating Kiwis could be paying at much as $4.4 billion in interest costs per year.

And its seems our use of credit is only on the rise.

In November Payments New Zealand released a report which found that while New Zealand currently spends more on debit cards it is shifting towards credit cards.

In 2010 New Zealand had 3.5 debit card transactions per credit card transaction but in 2014 this dropped to three.

On average New Zealanders spent $1.30 on debit for every $1 spent on credit in 2014 down from $1.35 in 2010.