Mortgage Pre-Approval Explained

Pre-approval is one of those terms everyone throws around during a property search, but I find a lot of buyers do not actually know what it confirms, and more importantly, what it does not. Getting this clear early saves a lot of confusion once you are actually under offer on a property.

What pre-approval actually is

Pre-approval, sometimes called approval in principle, is a lender's indication that, based on the information you have provided about your income, expenses, debts and deposit, they would be willing to lend you up to a certain amount. It gives you a genuine, realistic figure to search with, rather than guessing what you might qualify for.

It is conditional though. It is based on the information supplied at the time, and it still needs to be confirmed against the actual property you end up purchasing, along with a final check of your circumstances closer to settlement.

Most lenders issue pre-approval in writing, usually as a formal letter or document you can show to real estate agents when viewing properties or making an offer. This is often what people mean when they say a buyer is "pre-approved" in a competitive market, it is a genuine document, not just a verbal indication.

What pre-approval is not

Pre-approval is not a guarantee of final approval. Once you have a specific property under offer, the lender will still assess that property itself, which can affect the outcome. It is also not a fixed offer that ignores changes in your circumstances. If your income, expenses or debt levels change materially between pre-approval and settlement, the lender can reassess, and the outcome is not guaranteed to stay the same.

It is best thought of as a strong, genuine indication rather than a locked in promise. That said, for a straightforward purchase where nothing about your situation changes, pre-approval converting to full approval is the normal, expected outcome, not a rare exception.

What lenders assess

To issue pre-approval, a lender looks at your income, your regular living expenses, any existing debt including credit cards and loans, and the deposit you have available. They apply their own serviceability calculation, generally including a stress test at a higher interest rate than what you would actually be paying, to make sure you could comfortably manage repayments even if rates rise.

This is genuinely one of the areas where comparing lenders matters, since different banks weigh these factors differently, and the pre-approved amount can vary meaningfully between them for the exact same person. One lender might treat your overtime income generously while being conservative about a credit card limit you barely use, and another might do the exact opposite. Neither is wrong, they simply have different policies, which is exactly why running your situation past more than one lender, or through an adviser who already knows how each one tends to assess things, is worth the small amount of extra effort upfront.

It is also worth understanding that pre-approval is generally assessed against your circumstances as they stand, not a hypothetical future version of them. If you are expecting a pay rise, a bonus, or a change in your situation that would improve your position, that usually only counts once it has actually happened and can be evidenced, not while it is still anticipated.

Pre-approval versus full approval

It helps to be clear on where pre-approval sits in the overall process. Pre-approval happens before you have a specific property, based on your general financial position. Full, or unconditional, approval happens once you have a property under offer and the lender has assessed that specific property, alongside a final check that nothing material about your own situation has changed.

In practice, for most straightforward purchases, this final step is a formality rather than a hurdle, provided the property itself is unremarkable and your circumstances have stayed steady. Where it becomes more involved is with unusual properties, such as those needing significant repairs, or where something about your financial position has shifted since pre-approval was issued.

Documents you will need

Typically you will be asked for recent payslips or proof of income, two to three months of bank statements, a summary of your existing debts and regular expenses, proof of your deposit or savings history, and identification. If you are self employed, expect this to extend to financial statements and tax returns covering the last two years.

Having these ready before you start rather than scrambling once a lender asks genuinely speeds the whole process up.

How long pre-approval lasts

Most pre-approvals are valid for somewhere between 60 and 90 days, though this varies by lender. If your search takes longer than that, it can usually be renewed, sometimes with an updated check of your bank statements and circumstances to confirm nothing material has changed. It is worth knowing your expiry date and not letting it quietly lapse while you are still actively looking.

What can change your position before settlement

A few things commonly catch buyers out between getting pre-approved and actually settling. Taking on new debt, such as a car loan or a significant increase in credit card spending, can reduce what you are able to borrow. Changing jobs, particularly moving to a probationary period or a different type of income, can affect how a lender views your income stability. A drop in your deposit, for example spending savings you had earmarked for the purchase, obviously affects the numbers too.

Large, unexplained deposits into your bank account can also raise questions, since lenders need to understand the source of your funds as part of standard anti-money laundering checks. If a family member is gifting or lending you part of your deposit, it is worth mentioning this early rather than letting it come up as a surprise during final checks.

My general advice to clients once they are pre-approved is to keep their financial situation as steady as possible until settlement is complete. It is not the time to make large purchases or big financial changes if you can avoid it.

Why getting this right first matters

Buyers who skip pre-approval and go straight to house hunting sometimes fall in love with a property, only to find out afterwards that it is outside what they can actually borrow. That is a genuinely disappointing way to start the process. Getting pre-approved first means you search with a real number in mind, make offers with confidence, and avoid the emotional cost of chasing something that was never realistically within reach.

There is a practical negotiating advantage too. In a competitive market, sellers and agents take offers from pre-approved buyers more seriously than offers still subject to finance being arranged from scratch, since it signals you are genuinely ready to move. It will not replace a good offer, but it does remove one layer of uncertainty from the seller's side, which occasionally makes a real difference.

Frequently asked questions