The short answer
The lowest rate is not automatically the cheapest loan. Points paid upfront, lender credits, closing costs and how long you keep the loan all change the real cost. The right comparison is total cost over the period you realistically expect to hold the mortgage.
Part of our guide to Home Mortgages — what it is, what it costs, and who it suits.
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Rate shopping is the default because rate is the number everyone advertises. It is also the number most easily manipulated to look good, which is worth knowing before you compare anything.
What actually determines cost
- The rate, which sets the interest.
- Points, paid upfront to reduce that rate — a prepayment, not a discount.
- Lender credits, which reduce your closing costs in exchange for a higher rate.
- Closing costs, which vary between lenders more than buyers expect.
- How long you keep the loan, which decides whether upfront costs ever pay back.
That last one is the variable buyers most often ignore, and it changes the answer completely.
The break-even that decides points
Paying points lowers your rate, which lowers your monthly payment. Divide what the points cost by the monthly saving and you get the number of months until you are ahead.
If that break-even is four years and you sell or refinance in three, the points were a straightforward loss. If you stay fifteen years, they were a good buy.
Lender credits are the same trade, reversed
A lender credit reduces what you pay at closing in exchange for a higher rate. For a buyer short on cash to close, that can be genuinely useful. It is not free money — you are paying for it every month for as long as you hold the loan.
Same break-even arithmetic, running the other direction.
Closing costs vary more than people think
Origination charges differ between lenders, and the services you are allowed to shop for — title, settlement, some others — differ more. The Loan Estimate separates what you can shop for from what you cannot, which is a genuine opportunity most buyers skip.
The comparison worth doing
Take each offer and work out the total you will pay over the period you realistically expect to hold the loan: upfront costs plus payments over that span, less any credits.
Five years is a reasonable default for most buyers, and the Loan Estimate helpfully includes a five-year total. That figure is far more informative than the rate, and it is on a form you already have.
One thing worth more than shopping
Your credit score. The difference between rate tiers is usually larger than anything negotiation produces, and a few months spent paying down revolving balances before you apply can be worth more than every hour of comparison shopping.
If your purchase is six months away, that is where the effort pays best.
Common questions
Should I pay points?
Is the lowest rate always the best deal?
Can I negotiate closing costs?
Does my credit score really matter that much?
Products covered here
Where this comes up most
Read next.
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Getting a mortgage when you are self-employed
Why business owners get declined despite earning well, how lenders calculate self-employed income, and what to do two years before you buy.
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How to read a mortgage Loan Estimate
The standardised form every lender must give you, what each section means, and the three places two quotes most often differ.
Mortgages · 6 min
When refinancing costs more, even at a lower rate
Resetting the clock, rolling costs into the balance, and the break-even that decides whether a refinance is actually a saving.
Want this applied to your actual numbers?
Reading about it only gets you so far. One short application, a soft credit pull, and a straight answer about what fits.