1 (800) 685-7680 Us bank under writing department. Request for an increase through customer service then call that number and talk to uw. They pull Experian when applying for new card and all 3 when requesting an increase. I went from 800 to 25k. Then 25k to 33k. Now 33k to 50k. I love us bank. Also if you want something more flexible try Alliant credit union. They give generous lines up to 50k no annual fee. Great points and they work for the people not profit.