Money · Credit · New Zealand · Part 3
What actually limits how much credit banks can create?
If commercial banks create deposits when they lend, the obvious question is: what stops them creating as much credit as they want?
The answer is not one single rule.
It is a system of constraints operating at the same time: capital, liquidity, stable funding, credit risk, borrower demand, interest rates, macroprudential policy, regulation and the wider economy.
Banks can create deposits through lending. They cannot create good borrowers, unlimited capital, unlimited liquidity or unlimited real resources.
1. Capital: losses have to land somewhere
A bank loan is an asset to the bank. But not every loan will be repaid in full.
When borrowers default, the bank can suffer losses. Capital exists to absorb those losses before depositors and the wider financial system are put at risk.
The Reserve Bank requires locally incorporated banks to maintain minimum capital ratios relative to their risk-weighted exposures. Common Equity Tier 1 — the highest-quality form of bank capital — must be permanently available to absorb losses.
That means a bank cannot simply keep expanding its loan book without regard to the capital supporting it.
If lending grows, risk-weighted assets generally grow too. The bank must maintain enough qualifying capital against those exposures.
Reserve Bank: Capital requirements for banks ↗
The Reserve Bank has also been changing parts of the capital framework. Updated Banking Prudential Requirements are being phased in from October 2026, with some new credit-risk weights transitioning through to April 2027.
Reserve Bank: Capital and credit risk requirements ↗
2. Liquidity: a bank has to make the payment
Creating a deposit is one thing. Honouring payments is another.
If a customer transfers money to somebody at another bank, the customer's bank must settle with the receiving bank. It therefore needs access to settlement cash and other liquid assets.
The Reserve Bank's liquidity policy requires banks to hold sufficient liquid assets against projected cash-flow mismatches under stress.
It also imposes a core funding ratio, designed to make sure a meaningful share of a bank's lending business is supported by funding that is expected to remain stable for at least a year.
Reserve Bank: Liquidity policy for banks ↗
So even though a bank does not need to find the exact same amount of pre-existing deposits before every new loan, it still has to manage the funding and settlement consequences of the lending it creates.
3. Credit risk: creating a loan creates an obligation
The borrower has to repay.
That sounds obvious, but it is one of the strongest constraints on credit creation.
A bank that creates large volumes of loans to borrowers who cannot service them is not creating sustainable wealth. It is creating future losses.
This is why banks assess income, cash flow, collateral, debt levels, repayment history, business performance and the purpose of the loan.
Credit creation is therefore not merely a question of whether a bank can make an accounting entry.
It is a question of whether that accounting entry creates an asset that is likely to retain value.
4. Borrower demand: credit requires someone willing to borrow
Banks cannot force households and businesses to take on debt.
The Reserve Bank's Credit Conditions Survey tracks both the availability of credit and the willingness of households and businesses to use it.
The March 2026 survey showed a strong rise in observed residential mortgage demand and stronger commercial-property and corporate/institutional loan demand, while SME business loan demand remained slightly negative.
That is a useful reminder that the quantity of credit created depends not only on what banks are prepared to supply, but also on what borrowers actually want.
Reserve Bank: Credit conditions ↗
5. The OCR changes the price of credit
The Official Cash Rate is the Reserve Bank's main monetary-policy tool.
Changes in the OCR influence wholesale interest rates and, through the financial system, the interest rates households and businesses face on mortgages, business loans, deposits and other financial products.
Higher borrowing costs generally reduce the appetite for new debt and slow demand. Lower rates can encourage more borrowing and spending.
As at 29 August 2026, the OCR is 2.50%. The Reserve Bank increased it in July, saying the move was intended to help return inflation to target and avoid an unwarranted further easing in financial conditions.
Reserve Bank: Official Cash Rate ↗
Reserve Bank: July 2026 OCR decision ↗
The OCR does not switch bank lending on and off. It changes the price and financial conditions surrounding it.
6. Macroprudential rules can target particular risks
The Reserve Bank also has tools aimed specifically at financial-system risk.
These include capital and liquidity tools, the countercyclical capital buffer, sectoral capital requirements and borrower-based restrictions such as loan-to-value and debt-to-income measures.
These tools can make some categories of lending more expensive, require more loss-absorbing capital, or restrict the proportion of particularly risky loans a bank can make.
Reserve Bank: Macroprudential tools ↗
This matters because not all credit creates the same risk.
A dollar lent against an established residential mortgage, a highly leveraged property investment, a farm, a small business and a speculative project can have very different risk characteristics.
7. Inflation: the financial system ultimately meets the real economy
This is where the conversation becomes bigger than banking.
Credit creates purchasing power.
If that purchasing power expands faster than the economy's ability to provide goods, services, labour and productive capacity, prices can rise.
The Reserve Bank uses monetary policy to keep inflation between 1% and 3% over the medium term, with a focus on the 2% midpoint.
As at the latest published reading available on 29 August 2026, annual CPI inflation is 4.1%.
Reserve Bank: About monetary policy ↗
This is why "we can create credit" and "we can create unlimited real wealth" are completely different statements.
Money and credit can mobilise resources.
They cannot make scarce resources cease to be scarce.
8. The deepest constraint is productive capacity
Suppose New Zealand decides it needs more hospitals.
Financing matters. But after the financing is arranged, somebody still has to design them, consent them, build them, staff them and supply them.
The same applies to housing, electricity generation, roads, water infrastructure, schools, data centres and productive businesses.
This is why a serious national investment strategy cannot be only about money.
It must also be about:
skills
labour
materials
energy
land
technology
planning
execution capacity
and productivity.
The financial question is: can we fund it? The economic question is: can we actually deliver it?
This is where the public conversation usually becomes too simple
One side says:
"Banks create money, therefore money is unlimited."
That is wrong.
The other side says:
"We cannot build it because there is no money."
That can also be an incomplete answer.
The serious position sits between those slogans.
Modern financial systems can create substantial amounts of credit.
But that capacity is constrained by balance sheets, regulation, risk, inflation, demand and the productive capacity of the economy.
So before New Zealand decides that something is unaffordable, we should ask a more precise question:
Which constraint are we actually hitting?
Is it capital?
Liquidity?
Government fiscal settings?
Debt-servicing capacity?
Inflation?
Labour?
Materials?
Planning?
Or simply a decision about what we choose to prioritise?
The next question
Now we can move from commercial banking into the part of the system that is most often misunderstood.
Where does government money come from?
That means looking separately at taxation, government borrowing, New Zealand Government Securities, Crown bank accounts, settlement cash and the Reserve Bank.
And most importantly, we need to distinguish three things that are constantly blurred together:
commercial-bank money creation
government fiscal operations
central-bank money creation.
They interact, but they are not the same thing.
That will be Part 4.
Primary sources
Reserve Bank — Capital requirements for banks ↗
Reserve Bank — Liquidity policy for banks ↗
Reserve Bank — Credit conditions ↗