The RBA numbers on credit and debit card balances for February 2018 show some notable changes, and reinforce some well-established trends.The average credit card balance rose by A$94.10 to $3,180.70 in February - the largest increase in 2.5 years. In smoothed terms (12 month average) the average balance was down by 0.1 per cent. Among those credit cards that attract interest charges, the average outstanding balance rose by $39.70 in February to a two-year high of $1,990.50. The average balance accruing interest was up by 0.9 per cent on a year ago, noted CommSec's senior economist, Ryan Felsman."In smoothed terms (12 month average) the average balance was down by 1.5 per cent on a year ago," he said.Oher observations from CommSec were:•    the average credit card limit rose by $97.20 to $9,258.20 in February to be up 2.2 per cent over the year, although usage of credit card limits stood at 34.4 per cent in February;•    the number of credit card accounts stood at 16.581 million in February, down by 0.7 per cent over the year, whereas the number of debit card accounts stood at 46.616 million in February; up by 3.8 per cent over the year;•    continuing some other well-established trends: the number of ATM transactions in February were down 4.8 per cent over the year (a five-year trend in this case); and•    the number of debit card purchases in February was 15.7 per cent higher than a year ago with the value up 12.2 per cent, while 12.9 transactions were made on credit cards (on average) with 10.0 transactions made on debit cards. In analysing what these stats mean for investors and credit card providers, Felsman had this to say: "Aussies are spending again. The average credit card balance surged to two and a half year highs in February. The pick-up in plastic use mirrors the strong retail sales growth recorded during the month". He also suggested that improved job security on the back of record job gains are encouraging Australians to take on credit card debt. "Spending is preferred to saving. But the average value of purchases has declined to just $116.84 in February, and the annual growth rate of credit card accounts is declining," he said.