How Mortgage Pre-Approval Works
✅ Knowing What You Can Borrow Before You Shop
Mortgage pre-approval is a lender telling you, in advance, roughly how much it is willing to lend you to buy a home, subject to conditions. It is one of the first steps for most buyers, because it turns a vague idea of your budget into a concrete number, lets you shop with confidence, and shows sellers and agents you are a serious buyer. Understanding what pre-approval is, and what it is not, helps you use it well.
Why Get Pre-Approved
- Know your realistic budget before falling for a house you cannot afford.
- Move quickly and confidently when you find the right place.
- Show agents and sellers you are a credible buyer.
- Understand what you need to strengthen, like your deposit, before buying.
📝 What the Lender Checks
To work out how much it will lend, a lender looks at your whole financial picture. Knowing what they assess helps you prepare and present yourself well.
| What they check | Why it matters |
|---|---|
| Income | Shows your ability to make repayments |
| Deposit | The bigger the deposit, the lower the lending risk |
| Existing debts | Loans, credit cards, and buy now pay later reduce what you can borrow |
| Expenses and spending | Lenders assess whether repayments are affordable |
| Credit history | A record of how you have managed credit |
The Deposit and Serviceability
Two big factors stand out. Your deposit determines your loan-to-value position, and a larger deposit generally means easier approval and better options. Serviceability is whether you can afford the repayments, often tested against a higher interest rate than the current one, to make sure you could cope if rates rose. Our Borrowing Capacity Calculator gives you an early estimate of what you might borrow.
⏱️ Conditions, Limits and Time
Pre-Approval Is Conditional
A pre-approval almost always comes with conditions. Even once you have it, the lender will still need to approve the specific property you want to buy, because the home is the security for the loan. A property in poor condition, or one the lender values lower than the price, can affect the final approval even if your finances are fine.
It Has an Expiry
Pre-approval usually lasts for a set period, after which it lapses and may need to be renewed, with updated information. If your circumstances change in the meantime, a new job, a new debt, or a change in income, the pre-approval may no longer hold, so keep your situation stable while house hunting.
💡 Using Pre-Approval Well
Shop Within, Not At, the Limit
Your pre-approval is a maximum, not a target. Buying right at the top of your limit leaves no room for rate rises, rates, insurance, and the real costs of owning a home. Many buyers deliberately shop below their pre-approval to keep their repayments comfortable. See our guide on home affordability and use the First Home Buyer Calculator.
A Sensible Approach
- Tidy your finances first: reduce debts and unused credit limits, and build your deposit.
- Get pre-approved so you know your real budget.
- Shop below the limit to keep repayments comfortable.
- Keep offers conditional on finance until the specific loan is approved.
- Renew if it expires and keep your situation stable in the meantime.
Final word: mortgage pre-approval is a conditional indication of what a lender will lend, based on your finances, and it helps you house hunt with confidence. But it is not a guarantee: the specific property still needs approval, it expires, and it can lapse if your situation changes. Shop below your limit, keep offers conditional on finance, and treat pre-approval as a guide, not a cheque. This is general information, not personalised financial advice.
🎯 Test Your Knowledge
Quiz on Mortgage Pre-Approval (20 Questions)
Frequently Asked Questions
What is mortgage pre-approval?
A lender conditional agreement to lend you up to a set amount, giving you a clear budget and confidence to make offers.
How long does pre-approval last?
Typically a few months, after which it expires and may need to be renewed with updated information.
Does pre-approval guarantee a loan?
No. It is conditional, and final approval depends on the specific property, a valuation, and your circumstances not changing.
What do I need for pre-approval?
Proof of income, a record of your expenses and debts, your deposit details, and identification.