I've been watching my credit score for a while now on Credit Karma and it hasn't changed a single point. I think I might be at somewhat of a ceiling with regards to that...
Using their little simulator thing, even if I pay off almost all of my revolving debt, it still won't have much of any effect on my score. Even if I pay everything properly for the next 6 months... still nothing. I do have a theory though.
A few years ago I had a bit of a spell of late payments as I started to get behind and things started going badly for me - kind of all around. It was roughly June of 2006 that all of this happened... which ironically enough (or not) coincides with another event in my life. I think a few things got up to as much as 90 days late (one might even have been 120 days). 🙁
Unfortunately (along with my high balances and debt to credit ratio) this is a huge part of why my score is not as fantastic as it could be. Another part of the simulator let me see what happens if I make regular payments for the next 12+ months... THAT is where my score actually jumped up. So it looks like 4 years is some sort of magic number for those late payments. I'm sure they will stay on there longer than that - but it seems that might be at least one point where they affect my score less.
Assuming no other changes, my score would only increase 8 points with on-time payments for the next 3-12 months. At 15 months my score jumps 43 points. Ya... I'd say the late payments are part of the problem.