I am not sure why there is so much mystique and confusion about a credit limit increase from American Express. The request can be declined just like it can be with any other lender. There isn't some special thing you need to do before requesting one, just have the report looking its best. You can ask for a credit limit increase at 61 days with most lenders and you can ask for a 10x increase if you want. The major difference is that a lot of lenders perform a hard inquiry and American Express does soft inquiries.