How Lenders Calculate Your Living Expenses

When you apply for a mortgage in New Zealand, lenders do not just look at how much money comes in. Under the Credit Contracts and Consumer Finance Act (CCCFA), they are also required to form a realistic view of how much you spend, because it is the gap between income and outgoings that determines whether you can genuinely afford to service a loan. How lenders calculate your living expenses has a direct bearing on how much you can borrow, and it is an area of the application process that many borrowers are underprepared for. At Chaperone, we think understanding this process clearly is one of the most practical things you can do before you apply.

Why Living Expenses Matter So Much

Mortgage serviceability is essentially an assessment of how much of your income is available to make loan repayments after all other costs are accounted for. If your income is $10,000 per month but your assessed living expenses and existing debt obligations are $7,500, the lender sees only $2,500 available for a mortgage repayment. That ceiling directly determines the maximum loan amount they are willing to approve. Even small differences in assessed living expenses can shift your borrowing capacity meaningfully, which is why this part of the application deserves careful attention.

The Two Approaches Lenders Use

New Zealand lenders typically use one of two methods to assess living expenses, or a combination of both. The first is the Household Expenditure Measure (HEM) benchmark, a standardised figure based on research into typical household spending patterns. HEM benchmarks are adjusted for household size and income level, and they represent a floor rather than a ceiling: lenders use the higher of HEM or your actual declared expenses.

The second method is a detailed review of your actual bank statements, usually covering three to six months of transaction history. The lender or their assessor will categorise your spending across a range of categories including food, utilities, transport, entertainment, subscriptions, insurance, clothing, and any other regular outgoings. This approach can reveal spending patterns that a self-declared figure would not capture, and it is increasingly common as part of thorough CCCFA compliance.

What Lenders Look For in Your Bank Statements

When reviewing bank statements, lenders are looking for several things beyond just the total monthly spend. They are assessing whether your spending is consistent and predictable, whether there are any unusual or one-off items that inflate a particular month, whether there are signs of financial stress such as regular overdraft use, whether gambling transactions are present, and whether the pattern of spending is compatible with someone who could reliably meet mortgage repayments. A single month of unusually high spending is generally not disqualifying, but a pattern of living beyond your means over several months will be noted.

The Role of Discretionary Spending

Not all spending is treated the same way in a living expenses assessment. Essential expenses such as groceries, utilities, rent, insurance, and transport are non-negotiable items that will always be counted. Discretionary spending, such as eating out, entertainment, travel, and subscriptions, is also included but it is an area where you have more control. Lenders understand that people's spending patterns shift when they become homeowners, particularly if they are currently renting and redirecting that rental payment into a mortgage. However, they cannot assume future spending reductions they cannot evidence.

In the months before applying for a mortgage, many borrowers find it useful to review their discretionary spending and bring it into line with what they genuinely expect to spend as a homeowner. This is not about temporarily reducing spending to pass an assessment and then reverting afterwards; responsible lending requirements are intended to reflect sustainable behaviour, and presenting an artificially lean expense picture can create real problems down the track.

Liabilities Are Separate from Living Expenses

It is important to understand that living expenses and existing financial liabilities are assessed separately. Credit card repayments, car loan instalments, student loan repayments, and any other debt obligations are added on top of living expenses in the serviceability calculation. This means that high existing debt levels compound the effect of living expenses, reducing the available capacity for a mortgage even further. Reducing existing liabilities before applying is one of the most direct ways to improve your borrowing capacity.

Preparing for the Living Expenses Assessment

The most effective preparation involves reviewing your actual spending honestly, using three to six months of bank statements as your reference point. Identify any temporary or one-off items that are not representative of ongoing spending and be ready to explain them if asked. Make sure you are accounting for all regular expenses including annual ones such as insurance renewals or car registration, averaged into a monthly figure. At Chaperone, we can connect you with a mortgage adviser who will help you understand how lenders are likely to view your current financial position and what preparation will have the greatest impact on your application outcome.