There is no set time, you can ask whenever you want. But for best results you should give it some time and use the card responsibly.
CHASE FREEDOM | AMEX BCE | | BOFA REWARDS | CITI TYP | Quicksilver | DISCOVER IT | Sallie Mae | CHASE CSP
--------$32,000-------------$30,000-----------$30,000-----------$30,000-----$13,000---------$18,200----------$15,000---------$6,500----
FICO - TU: 780 EX: 784 EQ: 781
