We all know we're supposed to pay our bills on time and not max out our available credit—the two major factors that go into calculating our credit scores. Yet, there are other, smaller factors many people aren't aware of that can also have an impact on our scores.

1. Small Unpaid Debts

Some people pay their mortgage, credit card, and car loan bills with unflappable consistency, yet neglect their smaller debts. They may feel these debts are less important or that they will just go away if ignored. But very often they won't. Municipalities were once known to report unpaid parking tickets and even library fines to credit bureaus, for example, although that practice has largely been curtailed. Still, other unpaid debts, however trivial they may seem, can weigh down your credit score.

2. Utility Bills

Your electricity or gas bill is not a loan, but failing to pay it can hurt your credit score. While utility companies don't normally report a customer's payment history, if your account becomes delinquent and they turn it over to a collection agency, that will show up on your credit report as a serious negative.

3. Too Many Recent Credit Applications

It can be tempting to sign up for new credit cards that offer an attractive bonus or other perks. Banks may offer tens of thousands of points or airline miles, while retailers provide in-store discounts when you apply for their credit card. A single application may have little effect, but too many in a short time period can lower your credit score. So limit your number of applications for credit, especially if you are getting ready to shop for a home, car, or student loan, where a strong credit score could be extra important in getting approved and landing a good interest rate.

4. Long-Term Loan Shopping

To allow consumers to shop around for the best rates on auto, home, and other loans, FICO (the best-known credit scoring system) doesn't penalize people whose credit reports show multiple credit inquiries in a short period of time. Various FICO formulas discount multiple inquiries within either 14 or 45 days. However, continuing to shop around for a loan over several months will fall outside of this safe harbor and likely lower your score.

5. Business Credit Cards

Do you have a credit card for your business? If you are the primary account holder on the card, most banks will hold you personally responsible for any debts you rack up with it, as well as reporting your payment history to the credit bureaus. Late payments or unpaid debts will affect your personal credit, so be sure to use any business cards as judiciously as your personal ones.

6. Mistakes You Didn't Make

This is one of the reasons consumers are encouraged to check their credit reports at least annually and dispute any mistakes they find. You can obtain free credit reports at least once a year from each of the three major credit bureaus—Equifax, Experian, and TransUnion—through the official website, AnnualCreditReport.com.

7. Missing Accounts

Sometimes the problem isn't what's in your credit report but what's not in it. Some of your creditors may not supply information to any of the credit bureaus. That could mean a lower credit score if, for example, a credit card you have a pristine record of paying off on time isn't included in your report, while another, where you've missed a payment or two, is.

If you find any such accounts have been left off your report, FICO suggests you either "ask your creditors to begin reporting your credit information to credit bureaus" or "consider moving your account to a different creditor who does report regularly."

The Bottom Line

While paying bills in a timely fashion and not using too much credit at any given time are the two most heavily weighted factors in your credit report (commonly accounting for 65% of your score between them) if you want to maintain a high credit score, you should also pay attention to some other factors. Those include not applying for too much new credit and not allowing any damaging errors you find on you credit reports to go uncorrected.