Higher Credit Limits Can Increase Your Credit Score
A key factor in credit scoring is the ratio of your available credit to the amount of credit you currently use. The lower the ratio meaning the less you borrow compared to what you could borrow the more positive the impact on your credit score. One way to increase your credit score is to ask for and receive a higher credit limit. That way your current debt instantly makes up a smaller percentage of the total debt available. Your ratio drops, and your score should increase.
Just keep in mind that if you spend the credit available, your ratio goes back up and so do your monthly payments and your total debt.