I have a few credit cards that I use regularly - but I started only using one card for everything about a year ago. Even though I pay the whole balance off every month, and don't ever carry a balance from one statement to the next, just because I was always up against my credit limit on that card it lowered my score over 40 points. My report said that I was continually carrying a high balance on a card, which indicated to the credit scoring agency that I might be overextended. That couldn't be further from the truth - I was paying off the balance every month, and was just using that card for everything because I liked getting the cash back bonus. But, just that one card caused my score to go from one that was in the top 98% of all borrowers to one that was better than 75% of borrowers. When I went back to spreading my purchases across all cards and paying cash more, after a few months, my score went right back up to where it was before.
Companies that rate your credit look at your debt in relation to amount of available credit. It's a mildly ******** way to evaluate someone's creditworthiness, and I believe it's one of the things that will soon change in the algorithm they use to come up with your credit score. I, like you, carry massive balances per month on my CC's, but I also pay them off each month before interest gets applied.
This annoys the credit companies.
A credit rating would more aptly be named if it was called a "profit probability assessment". They are less concerned about a person repaying the debt than they are making the most money possible off that person. You see, you don't carry a balance, so they can't charge you interest. That's a major revenue stream you're ruining for them. They prefer people who carry a balance, have finance charges applied to their accounts, but who still make their monthly payments on time. And you know who they REALLY love? The guys who are late once or twice a year, which enables them to immediately inflate the APR to something the mafia would charge, but who still make their payments. Those guys are gold mines, but they'll never say that aloud. You can't even factor that into the algorithm because consumer rights groups would pick up on it. The ideal CC holder is a person who carries near a maximum balance, is late once or twice per year, but who still makes all his payments. They make the most profit off that guy.
But if your credit rating went UP for being late with your payments a couple times, people would cry foul. People already get annoyed, and rightly so, that paying off their balances every month, or even never using their credit card, actually HURTS their credit score. I could understand it not having an impact, but to deflate your score for being responsible is rather irritating.
Having said all that, from a business standpoint, I understand the creditors. They are trying to make the most money off their investment, which is the money they let you borrow from them. I still don't like it, but I understand it.
From the lawyers and financiers I talk to, they say the sweet spot for balances is 1/4 - 1/3 of your available credit. Pay on time, take the finance charges. Even though it *****, the increase in your credit score and the associated lower interest rate on mortgages easily makes up what you spend on finance charges from your low balance CC.