Credit score / FICO

FICO – what do I need to get approved for a line raise?

I have a Barclaycard card that recently offered me a 5% balance transfer deal. I had a $0 balance on the Barclaycard card, and a $1500 limit.

I transferred $750 into it from a card that was charging 21%. I didn’t want to max it out, because I know that can hurt your rating (ratio of balance vs. total credit line). Plus the 21% card is a closed account, so my available credit on that account doesn’t mean anything toward my ratio. (?)

Anyways, my question is, if I have a FICO score of 640, is that high enough to call Barclaycard and request a line increase? If I can get my credit line up to say, $2500, I could then transfer another $1000 or so from another high interest card and still have some padding left over to make it a good ratio.

What I DON’T want to do, is request a line increase and get shot down, because I know those inquiries hurt your FICO. But I’ll risk it if there’s a good chance I can get approved for the increase.

So who out there can give me some advice on this? Should I wait a few more months until it’s over 670?

P.S. Barclaycard cardholders have access to their FICO score for free and is updated monthly. I strongly recommend anyone who is concerned about their score to try to get an account with them, instead of paying to see your score.