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If you're in the market for your first home, the process may seem pretty daunting, especially getting your first mortgage. However, the more you know about mortgages, the better prepared you'll be, so here are 15 things you should know that can get you ready for the application process and possibly save you thousands of dollars.

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1. Know your credit score and what it means to your mortgage

Your credit score can make a big difference in how much home you can afford and how much interest you'll end up paying. For example, if you're obtaining a $200,000 mortgage and have a FICO score of 750, you can expect to pay $138,324 in interest over the term of a 30-year mortgage as of this writing. On the other hand, with a score of 650, you can expect to pay almost $35,000 more. MyFICO.com has an excellent calculator that can tell you the cost of your credit score. Before you start the homebuying process, it can be a good idea to check your credit report and FICO score and to do damage control if necessary.

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2. Estimate how much you can borrow

Lenders generally use two different debt ratios to determine how much you can borrow. The short version is that your monthly housing payment (including taxes and insurance) should be no more than 28% of your pre-tax income, and your total debt (including your mortgage payment) should be no more than 36%. The ratio that produces the lower payment is what the lender will use. Many lenders have more generous qualification ratios, but these are traditionally the most common.

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3. Don't overextend yourself

If you have a credit card with a $20,000 limit, that doesn't necessarily mean that you should spend $20,000 on purchases with the card. The same logic is true when it comes to mortgages -- just because you can qualify for a certain mortgage amount doesn't mean that you have to max out your budget. Be sure that your new mortgage payment not only fits your bank's standards but your budget as well.

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4. Get your documentation in order

When you apply for a mortgage, you'll need to document your income, employment situation, identity, and more, so it can be a good idea to start gathering the necessary documentation before you walk into a lender's office. This isn't an exhaustive list, but you should locate your last couple of tax returns, bank and brokerage statements, pay stubs, W-2s, driver's license, Social Security card, marriage license (if applicable), and contact numbers for your employer's HR department. Here's a more comprehensive list that can help you determine what you'll need.

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5. Get a mortgage pre-approval before you start shopping

To be clear, you don't need a pre-approval to start looking at houses. However, since a pre-approval is essentially the same as a full mortgage approval, just without a specific home in mind, it can be an extremely valuable shopping tool. Specifically, if you submit a pre-approval along with your offer, it tells the seller that you're a serious buyer who is not likely to run into trouble when obtaining financing. One caveat: A pre-approval and pre-qualification are two different things. A pre-qualification is based solely on information you provide and is not a commitment to lend money, therefore it doesn't carry nearly as much weight.

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6. How much of a down payment do you have?

The mortgage industry standard is a 20% down payment. However, you may be able to get a conventional mortgage with significantly less money up front -- as low as 3% of the purchase price in many cases. Specialized loan types, such as VA and USDA mortgages require no down payments at all for those who qualify. The point is that while a higher down payment will lower your monthly housing costs, you may be able to get into a home with less money in savings than you think.

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7. Closing costs don't have to add to your out-of-pocket expenses

Generally speaking, you can expect closing costs to be in the neighborhood of 2%-3% of your mortgage principal amount. So, on a $200,000 mortgage, you can expect a bill of up to $6,000 that must be paid when you get the keys.

However, it's perfectly acceptable to work seller-paid closing costs into your offer in order to reduce your out-of-pocket expense. In other words, if you want to offer $195,000 on a home, you can offer $200,000 and ask the seller to pay up to $5,000 in closing costs for you. This can be an excellent strategy for first-time buyers with limited savings to improve their ability to get a mortgage.

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8. Consider an FHA loan if your credit history isn't great

Typically, you'll need a minimum of a 620 FICO score to qualify for a conventional mortgage, and it can be difficult to qualify with a score that's near the minimum if your other qualifications aren't stellar. Another option is the FHA mortgage, which is designed for borrowers with qualifications that don't meet the standards of conventional lenders. The downside is that FHA loans can be significantly more expensive, but they can be great resources for people who otherwise wouldn't be able to qualify for a mortgage.

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9. Budget for mortgage insurance, if necessary

If you put less than 20% down on your mortgage, you'll probably have to pay private mortgage insurance, or PMI, so be sure to budget for this when shopping. Mortgage insurance rates can vary significantly, depending on your credit, the length of your mortgage, how much your down payment is, and other factors. However, it can add a significant amount to your payment, so be sure to take it into consideration.

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10. Shop around for a low rate

One common mistake among first-timers and repeat buyers alike is accepting the first mortgage that's offered. A seemingly small difference in rates can save you thousands of dollars over the course of a 30-year mortgage, and as long as all of your mortgage applications take place within a short time period, the additional inquiries won't have an adverse effect on your credit score.

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11. Don't forget about smaller lenders

When you're shopping around, don't just check the big national mortgage lenders. Some regional or local banks may offer unique lending programs, especially for first-time homebuyers. For example, the young couple who bought a house from me a few years ago used a 100% financing program from Regions Financial that required no mortgage insurance for first-time buyers with outstanding credit.

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12. Consider a 15-year mortgage

If you can afford the higher payments, or are willing to buy a less expensive home, a 15-year mortgage can save you thousands of dollars in interest and can allow you to own your home free and clear in half the time. Fifteen-year interest rates are about one percentage point lower than 30-year rates, and you might be surprised how much the combination of a lower rate and shorter amortization period can save you.

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13. Fixed or adjustable?

For the majority of homebuyers, a fixed-rate loan is the best choice, especially in a low-interest environment like we're in now. However, if you don't plan on being in the home you buy for more than a few years, an adjustable-rate mortgage could save you thousands of dollars in interest. For example, if you're buying a home to live in during four years of graduate school, an adjustable-rate mortgage with a five-year initial rate period could be a smart idea.

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14. Expect a few hassles before closing

In a perfect world, you could apply for a mortgage, have the home inspected, and show up at the closing table a month later to wrap things up. Sometimes that happens, but it's rarely that easy. More often than not, there are some hassles along the way.

As an example, when I was buying my first home, my lender called me three days before closing to let me know that my credit score had fallen to one point below the threshold for my interest rate, so I would either have to take an action that would improve my credit score immediately or accept a significantly higher interest rate. The solution required me to pay off one of my credit cards and fax proof of it to the lender -- not an impossible situation, but certainly a hassle when I was told it had to be done right away and I was at work.

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15. After you apply, don't use your credit until you have the keys in hand

Continuing on my last point, it's a good practice not to use your credit for anything out of the ordinary between the time you're approved for your mortgage and when you actually close on the home.

Lenders will generally pull your credit at least twice -- when you originally apply and shortly before closing (as happened in my situation). If there are any significant differences between the two, such as a new account or a significantly higher debt balance, it could lead to delays and could even disqualify you for the mortgage. Be safe -- just leave your credit alone until you've signed your closing documents.

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