Legal Question in Business Law in California

Apparently your error was in not obtaining a taxpayer identification number for the corporation, sometimes known as an employer identification number, but it's basically a number that serves about the same function as a social security number for an artificial (non-human) entity such as a corporation, partnership, LLC, etc.

It may be that you compounded the mistake by preparing applications, contracts, or other documents relating to the corporation's business without maing it 100% clear that you were signing for the corporation as an officer, and not in your individual capacity. The signature lines on a corporate agreement should read something like "XYZ Corporation, by John Doe, its Vice President" rather than just "John Doe".

At this point, you have two possible issues to deal with: your credit report and your possible personal liability for what should be a corporate debt. Credit-reporting agencies should be open to discussion with you about why your credit report should be corrected, but without more information I can't say that you'll be successful. As to possible personal liability, if you haven't been sued yet, you may not ever be, but remember that stockholders and officers can be held liable for corporate debts either under an "alter ego" theory, or if the corporation folds up and returns capital to its stockholders without paying its creditors in full first.