While spending on credit and charge cards has been weak over the past few years, card issuers have been able to count on steady, if modest, growth in account numbers. But over the past couple of months the number of credit and charge card accounts has fallen.According to the latest Reserve Bank data, card account numbers fell 1.4 per cent from 15.6 million to 15.4 million over the two months to April.Taking this fall into account, credit and charge card account numbers have grown by just 0.6 per cent over the 12 months to April.The number of purchases on credit and charge cards fell 2.3 per cent in April, compared with the previous month, and the value of purchases fell 7.4 per cent to A$21.3 billion.The average spend on a credit or charge card in April was $1380.The value of balances accruing interest was up a little - from $34.7 billion in March to $34.8 billion in April.Debit card spending was also down in April. The value of purchases on debit fell 4.4 per cent in April to $15.9 billion.