Economists estimate balances increased by $18.65 billion in June.
"Retail sales ex-auto were up another 0.4% mom in June, which suggests continued, steady momentum in revolving credit," said Bank of America Merrill Lynch economists. "Vehicle unit sales were strong in the month, which suggests that non-revolving credit is likely to continue to expand. The extension of student loans by the federal government also should boost non-revolving credit, although at a slower pace than the prior month."