When you purchase a home, the wheeling and dealing typically begins when you put an offer in. But home buyers who think the only opportunity to save big comes during those negotiations may miss a relatively effortless way to pay significantly less.

Comparing lenders is something just 50% of home buyers do, according to our analysis of data from the National Survey of Mortgage Originations. But comparing mortgage rates across five lenders before signing on the dotted line could save you hundreds of dollars in interest in the first year alone.

“The fun part about home shopping is touring houses, picking out decor and imagining friends and family seeing your new space,” says Holden Lewis, NerdWallet mortgage expert. "On the flip side, comparing mortgage rates can seem monotonous and stressful, but in reality it's an easy task that can lead to huge long-term savings."

According to a 2018 report by lender Freddie Mac, comparing five lenders can save borrowers an average of 0.17% on their interest rate. While a fraction of a percent may not seem worth the effort, the savings add up.

On an average-size home loan, comparing lenders could save borrowers $430 in interest in the first year, or $9,200 total over the 30-year mortgage. Each month, a savvy borrower could pay $26 less than their single-lender counterpart.

If keeping the excess money close at hand is a priority — if you’re putting it toward an emergency fund, for example — an online high-yield savings account is a good bet and, by the time the mortgage is paid off, could turn that $9,200 into $11,900. If you already have an emergency fund, certificates of deposit have higher interest rates and could yield $15,100 after 30 years.

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Getting the most bang for your savings means putting it a bit more out of reach. By contributing to an individual retirement account, the $9,200 in savings could be $30,200 by the time your home is paid for.

"Interest can harm or help your bottom line. When you pay interest on your mortgage, money is flying out of your pocket, but when you collect interest on your savings, you're building wealth," Lewis says. "By choosing a lower-interest mortgage, you're able to save and therefore earn more."

How to: Compare rates and save

Comparing lenders doesn’t mean you have to have lengthy phone conversations or even fill out paperwork. The Freddie Mac analysis suggests these comparisons can be made online with a mortgage comparison tool or by visiting lender websites. Getting preapproved may not be necessary to save on interest rates, but it can boost your bargaining power if a seller is considering multiple offers.

First-time home buyers should also look into local programs offered within their state. Many states have grants available to assist with down payments or special tax breaks and lower interest rates for first-time home buyers.

Finally, be smart about your down payment. A large down payment may not be possible, and you don’t want to dip into your retirement savings or emergency fund to buy your home, if you can help it. But the more you can put down, the smaller your loan will be. Put as much as you can down while maintaining your current financial security and setting aside enough for expenses like closing costs and future home maintenance.