Payment processing firm Paymark says discretionary spending dropped to 0.4% in March, which is below the same period a year ago.
The total value of transactions rose 4.2% in the March year, led by increased spending on food and liquor.
Paymark accounts for three quarters of all electronic payments.
Paymark head of sales and marketing Paul Whiston says people are choosing to repay debt rather than spend the money they have left over after buying the necessities.
Mr Whiston says the Canterbury region has almost recovered from a 31% plunge in spending in the weeks following the February earthquake.
Debit card use rose 6.5% while credit cards fell 2.5% in March.