I haven't tried that yet - only just made my first spend on mine as I applied from scratch. I'm surprised they gave me such a small credit limit given my income and not that many other lines of credit. I even applied for the "Prestige" card to maximize my chances of getting a decent limit - I wonder whether it matters if I applied for the $99 card or the $300 one - they said I can go through the application for a higher credit limit in 3 months. Might try that.