Welcome! Basically the way it works is that you need to watch what balance reports to the credit bureaus. For example, if I have a $500 limit, and I max out my card and it reports with that $500 balance, my score drops. FICO scores are very sensitive to utilization, and a maxed-out card means you are using all of your available credit.
But let's say I pay all but $10 off before the due date. The credit card company then reports a small balance, and my utilization looks good. I have a cap one secured card, so I pay it down by the due date, it reports a couple of days later, and then I am free to charge again if I want to. Does that make sense?
There's more about utilization here: http://ficoforums.myfico.com/t5/Rebuilding-Your-Credit/Your-Guide-to-Credit-Scoring/m-p/718550#U7185...
and you should read this, just because it's full of good info.
If you only have one CC it is never a good idea to let it report a 0 balance. FICO doesn't like to see you not using your credit. Not as much as over using it though.
I think what you may be referring to is if you is letting the CCC see you make big purchases and pay them off promptly. It lets them know you are capable of handling higher limits and will give CLI sooner.
You can use as much of the limit as you like as long as it is paid down to 9% or under before they report the balance to the CRAs. That is normally around the time the statement cuts. Then you can pay off the rest before the due date to keep from paying interest.
Alternating cards is also a good idea, if you have more than one, so the other CCC sees you use their card.
You saw that huge jump because your utilization dropped significantly. Doing what you are talking about will not make a difference in your score because the cards would not report the huge balance. That is why they pay them off before they report.
Some do not carry a balance and it fits their situation. For the most part, letting is small balance report is what gives the best score.
You have the right idea...
For example, my cc statement cuts on the 16th and reports on the 20th. I can do anything I like with the card all month except around those dates. I need to pay in full before the 16th and let whatever balance I want to report post by the 20th (ex $30 on $1k line).
Are you sure there were no other changes to your report for the score jump? That is an unusual increase if it previously reported at 15%. Maybe since it is your only revolving line?
It was previously maxed out then he paid in full to get that jump in score. That would do it.
FICO doesn't like to see you not using your credit. Not as much as over using it though. Thanks I learn something new everyday. Joining this community has helped me rebuild my credit.
Normally, when you are added as AU you get the cards history instantly. If your oldest is only a year and hers is 10, yes it will definitely help AAoA.
Does it have pristine payment history?