Most credit card creditors report monthly to the 3 credit agencies, and some report every other month. The day of the month in which they report also varies.
If you, say, paid off all your debt March 5th, you might not see these new balances reflected in your report until usually no earlier than end of March, and USUALLY more likely around mid to late April and in some instances not until as late as the beginning of June.
If you're in a rush, you can sometimes dispute the report using the 'incorrect balance being reported' option or somethign like that, which will open an investigation whereby the investigator at the credit agency will contact the creditor and verify the current balance and then update it. I don't necessarily recommend this, however, unless you're in a huge rush. The downside is possibly having some credit history showing 'customer disputes account' remarks which may or may not be seen by future creditors---who may in turn view you as potentially a "high maintenance" customer and perhaps less desirable... but that's only conjecture on my part.
