I did have a problem once obtaining a mortgage because I had too many credit card accounts open. They told me that they took the total credit available to me on all accounts and figured out the minimum monthly payments on that, and then used that against my total income. Some credit cards keep increasing your credit line and you really don't notice - I had one over $14,000 - which can count against you. I now keep just 4 or 5, Starwood Amex, AAdvantage MC, Hilton Amex, Hilton Visa, and 1 that I open and close to get bonus points.