Capital One Financial Corp. and Alliance Data Systems Inc. on Monday both reported increases in net charge-off rates for May. The annualized charge-off rate for Capital One's $67.9 billion credit card portfolio rose 20 basis points, to 6.28% from 6.08% in April. The portfolio's 30-day delinquency rate was 3.81% in May, down from 3.9% in April, according to a Cap One filing with the U.S. Securities and Exchange Commission. The delinquency rate has decreased incrementally since the start of the year. In January, Cap One reported its delinquency rate at 4.36%. Alliance Data officials reported that the net charge-off rate in its master trust declined 138 basis points from April but climbed 53 basis points from a year earlier, to 5.28%. Alliance Data issues private-label credit cards.