As mortgage lenders tighten approval standards nationwide, the importance of a good credit score is rising. Credit scores not only make the difference between a mortgage approval and mortgage turn-down, but they also play a large role in determining your actual mortgage note rate.

In the 3-minute piece, the NBC Today Show talks about 7 ways that homebuyers ruin their credit -- often by accident. Some of the highlighted mistakes include:

• Closing open credit cards
• Making appliance buys on credit prior to closing
• Asking creditors to lower credit balances prior to closing

In general, a 740 FICO will insulate a borrower from the higher costs and/or rates associated with low credit scores. Below 740, though, every 20 points adds to the damage. Watch the video and apply what you can to your own situation. The more you know, the more you can save.

FHA home loans are federal assistance mortgages made by lenders, and backed by the government. The FHA doesn't make loans to homeowners -- it insures loans made to homeowners by federally-qualified lenders.

By all accounts, FHA home loans are surging in popularity.

• 2006, FHA insured 3.3% of all mortgages made
• Q2 2009, FHA insured 19.2% of all mortgages made

A major reason for the increase can be tied to guidelines.

As compared to its conforming mortgage cousins Fannie Mae and Freddie Mac, FHA home loans have lower downpayment requirements and looser credit standards. The FHA allows downpayments of 3.5 percent and Fannie Mae and Freddie Mac do not, as an example.

Another reason is that FHA home loans aren't subject to credit score fees the way that conforming mortgages are. Through Fannie or Freddie, a home buyer with a 650 FICO and 20% down is subject to 3% in risk fees. Via the FHA, the fee is zero, making FHA the better "deal".

The FHA published its 2010 loan limits. There's no change from 2009.

The base 2010 FHA loan limits are:

• 1-unit : $271,050
• 2-unit : $347,000
• 3-unit : $419,400
• 4-unit : $521,250

We say "base" because these loan limits don't apply to all areas equally. Higher-cost regions get higher loan limits, based on typical home values. Homes in Los Angeles County, for example, can be FHA-insured up to $729,750 in 2010, and there are special exceptions made for Alaska and Hawaii.

The official FHA announcement included a complete, county-by-county FHA loan limit list. The first spreadsheet shows each county at or above the $729,750 maximum; the second list is everyone else.

If your home's county is on neither list, use the "base" numbers above.

Fannie Mae raised the bar for mortgage applicants this past weekend. Getting approved for a home loan just got harder.

In its official announcement, Fannie Mae says the updates minimize long-term lending risks. If that's the case, this won't be the last guideline change Fannie Mae makes -- especially with loans defaulting at an above-normal clip.

The immediate changes are major. The first pertains to credit scores.

Effective December 13, 2009, the bulk of Fannie Mae's loans require a 620 credit score minimum. There are very few exceptions.

A second relates to loans with private mortgage insurance.

Homeowners whose loan-to-value exceeds 80 percent now have a choice:

1. Pay higher mortgage insurance premiums month-after-month
2. Pay a one-time fee paid at closing to compensate for higher risk

Both options result in higher consumer loan costs.

A third change concerns maximum debt-to-income ratio. Fannie Mae will no longer approve loans with debt ratios exceeding 45 percent except with very strong assets and very high credit scores.

In no case whatsoever may debt-to-income exceed 50 percent.

There are other changes, too, including the elimination of seldom-used mortgage products and additional risk-based fees for "expanded level" mortgage approvals. These updates affect just a small part of the population.

So, home prices are rebounding, mortgage rates are low, and -- for 5 more months at least -- there's a federal tax credit for qualified buyers. You don't have to buy a home now, but with mortgage guidelines sure to tighten in 2010, now may be a better time than later.

The best "deal" won't matter if you can't get qualified on your mortgage.

'Tis the season to do shopping -- and get bombarded with offers to open credit cards.

The deals are tempting, too. "Open a charge card today" and save up to 20% on your purchase. Considering that the average Black Friday ticket was $343, that's $68 saved per store.

For big-ticket items like televisions, the savings are even bigger.

But for people in the market for a new home -- or looking to refinance -- taking advantage of in-store savings could be a long-term money loser.

Every time you apply for a credit card, your credit score drops.

According to myFICO.com, "new credit" accounts for 85 out of 850 possible credit scoring points. New credit is defined by such traits as:

• Number of recently opened accounts
• Number of recent credit inquiries
• Time since credit inquiry(s)
• Proportion of accounts that are recently opened to all open accounts

Shoppers with few open credit cards are more likely to see their scores drop that shoppers with many cards.

Regardless, a credit score is worth protecting because of how mortgage rates are made. A conventional mortgage applicant with 20% equity whose FICO is 720-739 will be offered rates 0.125% higher than a comparable applicant at 740.

• For 700-719, the rate increases by 0.375%
• For 680-699, the rate increases by 0.750%
• For 660-679, the rate increases by 1.250%

Having a low credit score can be expensive.

It is okay to take advantage of in-store savings during the holiday shopping season, but it's also important to be aware of how your credit score may be affected.

If you're not applying for a mortgage in the next six months, you'll likely be alright. But, on the other hand, if you know you'll need your FICO soon, consider whether saving 15 percent on a $343 ticket is worth the long-term cost of a higher mortgage rate.

Beginning November 17, 2009, the FHA will make it harder to qualify for its popular Streamline Refinance program.

Available exclusively to homeowners with existing FHA home loans, the streamline program is meant to help homeowners reduce mortgage payments as simply as possible.

As such, the program carries minimum eligibility requirements.

In fact, the FHA Streamline Refinance is more notable for what it doesn't require from applicants.

• There's no income verification
• There's no asset verification
• There's no employment verification
• There's no appraisal required

The two biggest qualifiers, really, are that the homeowner meets a minimum credit score and that the new loan doesn't exceed the original balance of the old loan.

The new program guidelines, however, are much stricter.

Effective next month, among other requirements, applicants must show evidence of employment and income, plus proof of cash required at closing.

Furthermore, homeowners can't finance closing costs into the mortgage without a complete home appraisal. In areas of declining value, this may render refinancing with the FHA impossible.

Therefore, if you're a homeowner with an FHA mortgage, consider contacting your loan officer before the November 17 deadline to explore your Streamline Refinance options. Mortgage rates are low and you never know for what you'll qualify.

The worst thing you can do is to wait too long to find out. Once the deadline passes, the old guidelines will be history.