Mortgage Basics
The plain answer
Section titled “The plain answer”A mortgage is a loan used to buy a home, and the home secures the debt. You repay the amount borrowed plus interest over an agreed term. Compare the total cost, cash needed, rate risk, and loan rules, not only the advertised monthly payment.
How it actually works
Section titled “How it actually works”Principal is the unpaid amount you borrowed. Interest is the lender’s charge for providing the money. The interest rate determines how interest is calculated, while the loan term is the scheduled length of repayment.
Amortization is the process of paying a loan down through scheduled payments. Early in many mortgages, more of each principal-and-interest payment goes to interest because the outstanding balance is larger. Over time, more goes toward principal if you follow the schedule.
Several figures describe different parts of the loan:
| Figure | What it tells you | What it leaves out |
|---|---|---|
| Interest rate | The rate used to calculate interest | Some lender charges and nonloan housing costs |
| Annual percentage rate | A standardized yearly measure that includes the rate and certain borrowing costs | Property expenses and the exact cost if you sell or refinance early |
| Monthly principal and interest | The scheduled loan payment before other housing charges | Taxes, insurance, dues, maintenance, and utilities |
| Cash to close | The amount you are expected to bring to closing | Future payments, repairs, and ongoing ownership costs |
A fixed-rate mortgage keeps the interest rate unchanged for the loan term. An adjustable-rate mortgage can change after an initial period according to its contract. The adjustable option may start with a lower cost, but you accept uncertainty about later payments.
Your payment may also include escrow. Escrow is money the servicer collects and holds to pay expenses such as property taxes and homeowners insurance. The total payment can change when those bills change, even with a fixed interest rate.
The lender may transfer servicing after closing. Servicing means collecting payments, managing the account, and handling escrow. A transfer changes where you pay, not the terms in your signed loan agreement.
What this means for you
Section titled “What this means for you”Compare written loan estimates using the same purchase price, down payment, loan type, and time window. Rates can move, so quotes gathered under different assumptions or on different days can mislead you.
Check these items together:
- Interest rate and whether it can change
- Annual percentage rate and lender fees
- Loan term and total scheduled interest
- Monthly principal and interest
- Estimated taxes, insurance, and other charges
- Cash needed at closing
- Rules for mortgage insurance, rate locks, late payments, and early payoff
A shorter term usually raises the required payment but can reduce total interest. A longer term lowers the required payment but can keep you in debt longer and increase total interest. Choose the structure that fits a durable budget, then compare lenders on that structure.
Common mistakes
Section titled “Common mistakes”Do not choose a mortgage based on the lowest monthly payment alone. A longer term, adjustable rate, or added upfront cost can make the payment look better while shifting cost or risk elsewhere. Read the full estimate.
Do not treat the annual percentage rate as your actual interest rate. It is useful for comparing certain borrowing costs, but it does not predict your exact result if you pay early, refinance, or sell. Look at the rate, fees, and expected time in the loan together.
Avoid making major credit or job changes while the loan is being approved without speaking to the lender. New debt, moved cash, or a change in income can affect underwriting. Keep records for unusual deposits and respond to document requests promptly.
Related pages
Section titled “Related pages”Educational content, not personalized financial, tax, or legal advice. No affiliate relationships. Figures are for tax year 2026 and change annually.Read the full disclaimer.