Did you know that your credit reports may not reflect all your credit accounts? The truth is creditors aren't required to report anything to the major credit bureaus, so many lenders simply choose not to do so. Smaller credit unions, local retailers, student loan lenders, and gas card companies often fall into this category of non-reporting lenders.
If you were denied credit because you have "no credit" or an "insufficient credit file" even though you know you have open credit cards, you might consider reaching out to your lenders and requesting that they begin reporting your information to the credit bureaus. They may not listen to your request, but it never hurts to ask.
Likewise, you should always ask potential lenders if they report to at least one major credit reporting agency before choosing to do business with them. If they don't, consider taking your business elsewhere to make sure your credit history will benefit from your efforts to manage the account wisely.