It has always been my understanding that your credit score is "hard" pulled upon the application process and "soft" pulled for credit line increases.
The soft pull is what I was told by USAA when I did that one last year.
Credit card companies will ask you for income on the application. You could lie, but they also say they "may" ask you for records to prove what you say. I imagine if something doesn't jive by a lot the system will flag it for further documentation, or maybe they are just trying to scare the shite out of you.
I just went ahead and asked USAA for another manual limit increase. I threw in my 10,000 limit with Capital One, the fact I spent 2,000 a month on their card and my income. Hopefully they give me a good bump.
frick AMEX, I'm not even trying with them.
ETA: I stand corrected. I went for a modest increase from 1,100 to 2,000 and AMEX accepted it.
So, in a week I went from 4,100 to 15,000 in credit with one more request to go.
This post was edited on 1/21 at 10:12 pm