Five Factors That Affect Your FICO Credit Score. Credit scores range between 200 and 800. If Your Score is above 620 are then you are considered "desirable" for getting a mortgage. These factors can affect your score.

1. History for payments Did you pay your credit cards and other obligations in a timely fashion? Your score will be lower if you paid anything late.
2. What is your total debt? . If you owe a large amount of money on many accounts they may think you have extended youself too much.
3. A long credit history is better than a shorter one.
4. What is your total credit available? Newer credit, it can be installment payments or newer credit cards, these are seen as riskier, even when yo pay on time. Do not make any major purchases just before buying a house.
5. What types of credit do you use? . In most cases it is best to have more than one type of credit such as installment loans, major credit cards, and a home loan and so on.
   
   You can get a free credit report once a year from each of the main credit reporting agencies
   Equifax 1-800-685-1111 www.equifax.com
   Experian 1-888-397-3742 www.experian.com
   TransUnion 1-800-888-4213 www.transunion.com
   
   http://www.myfico.com - This gives you more info on understanding your score and how to improve it.