Considerations

• Applying for any type of credit lowers your score. Each hard inquiry into your credit history dings you three to five points. If you are applying for several other types of loans, getting a credit card magnifies your risk to lenders because needing loans is equated with a higher risk of default, according to TransUnion's True Credit.
  
  

Benefits

• Ten percent of your FICO score comes from using multiple types of credit successfully, according to the Fair Isaac Corporation. Adding a credit card when you already have a revolving loan lowers your credit utilities ratio--how much credit you use compared to the amount available, which counts for 30 percent of your score.
  
  

Potential

• Use your credit card sparingly, pay off your bill on time and you will improve your credit score even more. The FICO model weighs payment history the most: 35 percent of your score. If you have had credit problems in the past, using your credit card will help build your new credit--10 percent of your score.
  
  

Warning

• A new account will reduce the average length of your credit history, which counts for 15 percent of your FICO score. You will have to use your credit card for the lender to report good payment history. If you have a low credit limit, you can easily use more than 35 percent of your credit limit--the highest utilization ratio found in people with good credit.
  
  Credit cards, however, should boost your score if used properly and are often necessary to achieving the highest tier of score.