Unless your refinance mortgage is an FHA, VA, or USDA loan, the price you pay and the rate you get depend largely on your credit score and the amount of equity in your home. The good news is that there are steps you can take to improve your credit score, potentially saving you a bundle.

A quick look at the pricing schedules of Fannie Mae and Freddie Mac tells you all you need to know about mortgage pricing.

These schedules--known as loan-level pricing adjustments--are part of every mortgage loan officer's knowledge but are not well understood by the general public. Adjustments at 20-point intervals in your credit score (for example, from 620 to 639, then 640 to 659, and so on) add to how much you'll pay for your refinance mortgage.

Once you take a look, you'll see that raising your credit score from, say, 675 to 680 can make a huge difference in what you pay for refinance mortgage rates.

Increase your credit score with quick tweaks

Making huge improvements to your credit rating takes a sustained effort over time, but pulling it up a few points to get over a new credit score threshold can be done fairly fast. Here are a few quick and dirty techniques:

1. Become an authorized useron a friend or family member's credit accounts to add depth to your credit history. Many borrowers' credit scores are not as high as they could be simply because the consumer has not used much credit or held credit accounts for very long. If you have an excellent relationship with someone who has excellent credit, consider asking to be added as an authorized user. Make sure this person (and you) understand that you will not actually use their credit lines--you don't even need to know the account number to take this step.
   
   What this does is give you a larger amount of available credit, a longer credit history or a successful trade line or two. It's called "piggybacking," and as long as you actually know the person whose coattails you are riding and doing it with permission, there is nothing wrong with it.
2. Pay down balances if you canor ask for a credit limit increase from creditors with which you have a good track record. Your credit utilization, or the amount of available credit that you actually use, counts for 30 percent of your credit score. If your utilization is too high, you can improve (i.e., lower) this important ratio by reducing the amount you owe and/or increasing the credit available to you. If you have old accounts that you haven't used in a while, dust them off and make a small purchase, making sure to pay your balance in full. This will get those older creditors reporting your wonderful payment habits if they haven't done so in a while.
3. Manipulate your charge cards. Charge accounts like American Express often don't report a maximum credit limit. Instead, many credit reporting bureaus use the highest balance you ever had with that account as your limit. If you've confirmed that that's the case with one of your accounts, consolidate: make all of your purchases (gas, groceries, cable bill, whatever you can) with a single card for one billing cycle to set a personal best for charging in that month. Then pay it all off. Voila! A new higher limit and a reduced utilization ratio. If you do this, though, make sure you don't run afoul of your actual maximum credit limit.
4. Call in a favor.If you've been a good customer but have a small late booger on a credit account, the creditor might agree to wipe that one late payment from your credit history. You usually have to make the request in writing, and your chance of success depends on how good a customer you've been. For more serious infractions, you could ask that your account be "re-aged." This means the lender might delete previous delinquencies if you make a series of on-time payments or pay a lump sum.
5. Dispute incorrect information. Your refinance mortgage lender can refer you to a service called Rapid Rescoring, which can get inaccurate credit information deleted from your credit report in as few as 72 hours. The cost is reasonable. Note that you must have proof the item is incorrect--this isn't a credit repair scheme but rather a service that helps scrub truly erroneous items from your credit history quickly.

How much could you save on a refinance?

Is all this work to eke out a few more credit score points worth it? Especially if you're on the cusp of a higher 20-point credit score category, the answer is likely yes. The amount you could save on your refinance mortgage of course depends on your home's appraised value, the size of your loan, and whether you are refinancing a condo or manufactured home or taking cash out.

But on a plain-vanilla 30-year mortgage at 85 percent of your home's value, improving from 679 to 680 can save you a full point off of your fees, and improving to 720 saves another 0.75 percent. On a $300,000 mortgage, that's $3,000 for the first one-point increase and $2,250 for the next 40-point increase. Thousands of extra dollars in your pocket when you refinance is probably worth the effort.