First, I will answer your question, then provide you some advice based on 23 years as a mortgage professional.
If you had other mortgage inquiries in the past 30 days, the system treats a new mortgage inquiry with no effect. The original mortgage inquiry may have an effect, but your score won't drop much. (*see quote from myFICO.com below)
Fair Isaac is the company that created and continues to upgrade and maintain the credit scoring systems. Their website clearly indicates how mortgage inquiries affect a credit score.
From myFICO.com: â€œDoes the formula treat all credit inquiries the same? No. Research has indicated that the FICO score is more predictive when it treats loans that commonly involve rate-shopping, such as mortgage, auto and student loans, in a different way. For these types of loans, the FICO score ignores inquiries made in the 30 days prior to scoring.
Will my FICO score drop if I apply for new credit?
If it does, it probably won't drop much. If you apply for several credit cards within a short period of time, multiple inquiries will appear on your report. Looking for new credit can equate with higher risk, but most credit scores are not affected by multiple inquiries from auto, mortgage or student loan lenders within a short period of time. Typically, these are treated as a single inquiry and will have little impact on the credit scoreâ€œ
Here is the link: http://www.myfico.com/CreditEducation/CreditInquiries.aspx
Next, let me say this to you as a word of friendly advice (and caution): when you say you are working with different banks and mortgage brokers you're actually doing yourself a disservice. Shopping around is one thing, but "working with" many different mortgage professionals is ultimately bad for you as a consumer. Would you visit five different Doctors when you have the flu? What you should do is identify the professional you wish to work with based on knowledge, experience and terms, then stick with that professional.
Why is "bouncing around" a disservice to yourself?
Because you'll lose out on the opportunity to be guided through your home purchase or refinance by a serious and dedicated professional. Believe me, we KNOW when you're bouncing around. Then you'll be stuck with the novice, the amateur, the time-waster or, worse, the scam-artist-liar Loan Officer. And they are DEFINITELY out there. I know because I'm constantly asked to step in after the fact to help a consumer who made the wrong mortgage choice and now finds themselves stuck with no loan approval and/or no loan closing.
Getting a mortgage loan in 2013 is incredibly challenging. Serve your best interests by creating a relationship with, and closing your loan with, an experienced mortgage professional. You can look up a Loan Originator's experience level on the NMLS Consumer Access website while you verify their license. (I noticed the other day that a Licensed Loan Originator who posted a ridiculous and incorrect comment here on Trulia had only 3 years experience in the mortgage industry. Previous experience? Managing a pizza shop.)
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