The simple answer is that your credit score changes whenever new information is introduced to your major credit reports. That means it will be updated each month, since we already know that credit card companies relay information to the major credit bureaus on a monthly basis.
Whether or not this monthly reporting benefits your credit ultimately depends on the average balance you carry on your loans and lines of credit as well as whether or not you pay your bill on time. While on-time payments, reasonable credit utilization and income increases will benefit your overall credit standing and approvability for a loan, the converse of those events as well as negative public records and even simply applying for a new loan or line of credit will hurt your score in varying levels of severity.
With all of that being said, it’s important to note that your credit score doesn’t matter all that much until it comes time to apply for a loan, a line of credit or a job involving a security clearance or the handling of money. Yes, bad credit leads to higher insurance premiums and may make it more difficult to lease a car or rent an apartment, but these costs pale in comparison to the price differential between mortgages for people with good and bad credit.
The best way to prepare your credit for an impending loan application is to start by pulling one of your major credit reports roughly 18 months in advance of your application date. This will give you time to dispute possible errors and devalue past mistakes. At least 12 months before applying, you may also want to open a new credit card account in order to augment your overall available credit and add more positive information to your credit reports each month. Finally, about six months before submitting your application, pull your credit again just to make sure there are no surprises.
Then, as long as you handle your accounts responsibly in the meantime, your credit score will be updated and pristine as possible by show time.