There are things that you can and must do if you want to raise your credit score. This should be a task on your to-do list all the time, since your credit score is not used only for when you are opening a new account somewhere, but plays a factor in being considered for a new job or job promotion, and is even being used these days by many car insurance companies since they claim to have evidence showing that people with lower credit scores make more insurance claims.
The other reason you should endeavor to raise your credit score is because studies indicates that the majority of consumers have errors on their credit reports. To further compound that statement, those errors do not self-correct or auto-correct, but will remain on your credit report for years until and unless you dispute the items.
You can get a free copy of your credit report once annually from each of the three major credit reporting agencies, and you should definitely do this. This free report does not show your calculated credit score – you will have to pay for that, but that is also something that you might want to be aware of after you get the errors corrected.
The biggest single thing you can do to raise your credit score is to consistently pay your bills on time. The calculation formula used by the credit bureaus will "forgive" one time late payments or missed payments if the remainder of your bill paying activities have been on time, as long as those late or missed payments do not become a habit or more frequent.
Keep in mind that as the name implies, a credit history is a historical account of your credit habits. If you were going through a tough time several years ago and have since gotten your act cleaned up, the most recent trend is that you pay your bills on time, despite the late payments from years ago. If this was the case, you are permitted to add a 100 word consumer statement to your credit report to explain that, for example, you were paying off unexpectedly high medical bills in 2003 which caused you to fall behind.
For your open credit accounts, ensure they are always up to date, and attempt to keep your balance under about 35% of your total credit limit. This shows responsible use of credit. Also ensure that your credit report shows your credit limit so that potential lenders do not think it is unlimited.
If you encounter a situation where you are going to fall behind, don't wait until it happens to talk to your creditors. Be proactive about it and let them know what is going on and the vast majority of the time, they will work with you, and chances are that with your open communications with them, they may not even put a negative comment on your credit report unless it becomes very serious.
If your goal is to raise your credit score, this task is not impossible but it is going to take some effort on your part. Know that your effort will be well worth it.