New accounts and inquiries are only 10% of your fico score. It can drop you at most 80 points or so. However, if you have short credit history or other blemishes on your credit such as high-credit card balances or late payments, this could make things worse. I have opened and closed several accounts lately. My score stays around 770 to 790. I do not have any credit blemishes and have reported credit card balances of less than 10% of my reported credit (on every card).