When requesting a credit card limit increase — check your credit again or just review your acct with them?

I was going to request a small limit increase of $500 from one of my creditors and was wondering do they check your credit file again AND your account with them or do they do one or the other, if one or the other which one??? Thanks in advance

which is the best secured credit card?

I need to build credit and having trouble getting a card since i am not on the books at my job. Any suggestions for a secured card?? Or any card that lets me open acct without listing my employer.