01
Who else lives in the house
The people affected by the decision are not necessarily the people making it. A conversation with them before the drawing rather than after a difficulty is the minimum this deserves.
Guide
Same words, two products, very different risks.
In New Zealand, revolving credit most commonly means a home loan feature. Using one to fund a business is a real and common decision, and it is a considerably bigger one than it appears.
MS
Matt Stiles Editor
Published 8 September 2026 Last reviewed 8 September 2026 Read time 12 min
The short version
Five lines about two different products.
- The mortgage version is consumer credit. A home loan account with a reducing limit, offsetting deposits, and consumer protections attached.
- The business version is commercial credit. A limit assessed on the business, priced higher, and without those protections.
- The rate difference is real and it is not free. The home loan is cheaper because a house is behind it, and that is the whole of the reason.
- Using one for business is common and consequential. It works, it is cheap, and it converts a business risk into a housing risk.
- Indicative only. This is general information rather than advice, and every figure is illustrative.
The two products
What each actually is.
The rows that matter most are the last three, which are about consequence rather than mechanics.
| Feature | Revolving credit home loan | Business line of credit |
|---|---|---|
| Assessed on | Personal income and the property | The business |
| Limit behaviour | Ordinarily reduces on a schedule | Fixed until reviewed |
| Deposits | Offset the balance directly | Repay the drawn balance |
| Rate | Home loan pricing | Business pricing, higher |
| Regulated as | Consumer credit, ordinarily | Business credit |
| Security | The home | The business, and sometimes property |
| What is at risk on default | The house | The business, and whatever was pledged |
The last row is the entire reason this guide exists. Two facilities that behave similarly day to day have completely different consequences at the point something goes wrong.
The consumer product
What a revolving credit home loan actually does.
It is a home loan structured as an account with a credit limit rather than as a balance with a repayment schedule. Income is paid into it, spending comes out of it, and interest is charged on the balance each day. Because everything sitting in the account reduces the balance, money waiting to be spent is offsetting interest rather than earning a deposit rate.
The limit ordinarily reduces on an agreed schedule, which is what makes it a home loan rather than a permanent facility. Without that reduction the loan would never be repaid, so the schedule is doing the job the repayment schedule does on a table loan.
Used as intended by a household with discipline, it is an efficient product. Used without discipline it is a loan that never reduces except by the mandated amount, which is the ordinary criticism of it and is a consumer question rather than a business one.
The decision this guide is really about
Funding a business on a home loan converts a business risk into a housing risk.
It is cheap, it is already approved, and it requires no application, which is why so many New Zealand businesses are funded this way. What it does is move the consequence of a business failure from the business to the family home, and it does so without any of the moments that would otherwise prompt the question, because no new facility was arranged and nobody signed anything. That is a decision worth making deliberately, with a solicitor and with everyone affected, rather than by drawing down on an account that was already there.
Worked example
What the rate difference is worth, and what it costs.
A business owner has a revolving credit home loan with $150,000 of available limit at an indicative 8%, and could obtain a business line of credit at an indicative 15%. The business would draw an average of $80,000.
On the home loan that costs roughly $6,400 a year. On the business facility it costs roughly $12,000, plus a line fee. The saving is around $6,000 a year, which is a substantial and entirely real number.
What the $6,000 buys is the removal of a firewall. Under the business facility, a business failure reaches the business and whatever was pledged. Under the home loan it reaches the house directly, with no company between the two. Whether $6,000 a year is worth that is a genuine question with different answers for different families, and the point of setting it out this way is that it should be answered rather than assumed.
Illustrative figures
- Average drawn
- $80,000
- Home loan at 8%
- ~$6,400 a year
- Business line at 15%
- ~$12,000 a year
- Annual saving
- ~$6,000
- What secures it
- The house
Illustrative on stated assumptions and rounded. Not a quote or offer of credit.
Before using a home loan for business
Four questions worth answering first.
02
What the lender was told
Home loan facilities are approved on stated purposes, and using one to fund a business may sit outside what was disclosed. Whether that matters is a question for the lender and for a solicitor rather than an assumption.
03
How the interest is treated
Interest on borrowing used for business purposes may be treated differently from interest on private borrowing, subject to the accountant’s confirmation, and the records that support that have to be kept from the start rather than reconstructed.
04
What the exit looks like
A business facility can be closed. Money drawn on a home loan becomes part of the mortgage and is repaid over the life of it, which is a much longer commitment than the business need that prompted it.
The tax point
Purpose matters, and records matter more.
The treatment of interest ordinarily follows the purpose the borrowed money was used for rather than the security behind it, subject to the accountant’s confirmation of how a particular arrangement is treated. That means business-purpose drawings on a home loan can be treated differently from private drawings on the same account.
What makes that workable is separation. Where business and private drawings are mixed in one account, establishing which interest relates to which purpose becomes a reconstruction exercise rather than a record, and the position is considerably harder to support.
The practical answer, where a home loan is going to fund a business, is a separate sub-account or split used exclusively for that purpose, set up before the first drawing. That is a conversation with the bank and the accountant that takes an afternoon and saves a great deal later.
The trade
What using a home loan gives and costs.
What it gives
- A materially lower rate than any business facility
- Availability without a new application or assessment
- A larger limit than the business could obtain on its own
- Deposits that offset the balance directly and immediately
- No line fee separate from the home loan arrangement
What it costs
- The firewall between the business and the family home
- A commitment repaid over the life of a mortgage rather than a business need
- Records that have to be kept carefully for the interest position
- A decision affecting people who may not be part of it
- The business building no credit history of its own
The other cost
A business funded on a home loan has no lending history.
A business that has never held a facility in its own name has nothing to show a lender when it eventually needs one. No conduct, no repayment record, no evidence of managing a limit, and frequently a set of accounts that look thinner than the business is because the funding sat outside them.
That matters at exactly the point the business wants to grow beyond what a home loan can support. The first application is then a first application, made by a business with years of trading and no credit record, and the terms available reflect that.
It is an argument for holding a modest business facility even where a home loan is cheaper, and using it enough to build a record. The premium on a small facility used lightly is a few hundred dollars a year, and what it buys is optionality the business will want later.
Method
How this guide was written, and its limits.
The description of the consumer product is general. Revolving credit home loans vary between lenders on limit reduction, offsetting and how they interact with other accounts, and the specific terms are set out in the loan documentation.
The tax point is deliberately framed as a question for an accountant rather than answered here, because the treatment depends on facts specific to the arrangement and the records supporting it. Inland Revenue is the primary source and the accountant is the right adviser.
Nothing here is legal, tax or financial advice. This site is not a lender, a law firm, a chartered accountant or a registered financial adviser, and a decision to secure business borrowing against a home is one to take with professional advice and with everyone affected.
Doing it properly
Three steps before a home loan funds a business.
01
Split the lending before the first drawing
A separate sub-account or loan split used exclusively for business purposes, arranged with the bank before any money moves. It costs nothing, it takes one conversation, and it turns the interest position from a reconstruction exercise into a record the accountant can rely on.
02
Talk to everyone the house belongs to
The people affected by the decision are not necessarily the people making it, and a conversation before the drawing is a different thing from a conversation after a difficulty. This is the step most often skipped and the one that matters most.
03
Decide what it is for, and for how long
Money drawn on a home loan becomes part of a mortgage repaid over decades. Naming the purpose and a repayment intention, and writing both down, is what stops a temporary business need becoming a permanent addition to the household debt.
The structural point
A company exists to separate two things, and this rejoins them.
A limited company puts a boundary between a business and the people who own it. That boundary is imperfect, because directors give guarantees and lenders take security, and it is not nothing. A business failure inside a company is a different event from a business failure that reaches the family home directly.
Funding a business on a home loan removes the boundary in the most complete way available, because there is no company between the borrowing and the house at all. The money was borrowed personally, secured on the home, and lent into the business by its owner.
That is not an argument that it should never be done. A great many New Zealand businesses were started exactly this way and it is frequently the only capital available. It is an argument that it should be done knowingly, with the boundary’s removal understood as the thing being traded for the lower rate.
The trade
What each route offers a business owner.
The home loan route offers
- A materially lower rate than any business facility carries
- Availability without a new application or a credit assessment
- A larger limit than the business could obtain on its own
- Deposits that offset the balance immediately
- No separate line fee beyond the existing home loan arrangement
The business facility offers
- A boundary between the business and the family home
- A facility that can be closed when the need ends
- Credit history in the business’s own name
- An interest position that needs no reconstruction at year end
- A decision that affects only the people who made it
The exit
What happens when the business no longer needs the money.
A business facility can be repaid and closed, and the arrangement ends. Money drawn on a home loan does not behave that way. Unless it is deliberately repaid, it becomes part of the mortgage and is repaid across the remaining term of the loan, at a rate the household is paying for decades.
That is the quiet cost of the cheaper route. A $60,000 business need funded on a home loan and never separately repaid is $60,000 added to a mortgage, and the interest paid across twenty years of it is considerably more than the annual saving that made the route attractive.
The remedy is the same discipline a term facility would have imposed. A repayment plan for the business portion, set when the money is drawn and treated as separate from the household mortgage, converts a permanent addition into a temporary one. Almost nobody does this, and it is the difference between using a home loan sensibly and using it by default.
The lender’s view
Why banks are comfortable with this, and why a borrower has more to weigh.
From a lender’s side, business borrowing secured on residential property is among the best-secured lending available. The security is liquid, well understood and easy to value, and the recovery process is established. That is why the rate is low and why the limit is generous.
None of that comfort transfers to the borrower. The lender’s risk is low precisely because the borrower’s exposure is high, and the pricing is a direct expression of that relationship rather than a favour.
Understanding it that way is useful, because it reframes the decision. The question is not whether a bank will allow it, since it will and readily. The question is whether the family wants the business risk sitting where the bank is comfortable putting it.
The comparison
What each rate costs on the same balance.
Running the same average drawn balance at a home loan rate and a business rate gives the annual difference, which is the number the decision should be weighed against. Indicative only, and not a quote or offer of credit.
Indicative interest cost
Weekly
$123/week
$533 /month $6,400 a year while drawn
$150,000
$5,000 $500,000
$80,000
Nothing drawn Fully drawn
8.00% p.a.
8% (secured) 30% (unsecured)
Indicative only. Not a quote or offer of credit. Actual rates, fees, and repayments depend on the business profile and the lender's decision.
Sending to Prospa
Your $150,000 scenario
$80,000 drawn at 8.00% . Prospa will ask a few quick questions, then provide a firm quote and funding if eligible.
Redirecting…
References
Sources
- Credit Contracts and Consumer Finance Act 2003
The statute governing consumer credit, which ordinarily covers a revolving credit home loan and not a business facility.
- Commerce Commission, consumer credit
The regulator responsible for consumer credit conduct in New Zealand.
- Inland Revenue, interest deductions
The published source for how interest on borrowing is treated, which is a matter for the accountant in any particular case.
- New Zealand Law Society
Referenced for the point that securing business borrowing against a home is a decision to take with legal advice.
- Reserve Bank of New Zealand, statistics
Context for the difference between New Zealand housing and business lending rates.
FAQ
Questions, answered
What is a revolving credit home loan?
A home loan structured as an account with a credit limit rather than a repayment schedule. Income is paid in, spending comes out, interest is charged on the daily balance, and the limit ordinarily reduces on an agreed schedule.
Is it the same as a business line of credit?
No. It is consumer credit assessed on personal income and secured by the house, with consumer protections attached. A business line is commercial credit assessed on the business and priced accordingly.
Why is the home loan rate so much lower?
Because a house is behind it. That is the whole of the reason, and it is also the reason the two products have such different consequences when something goes wrong.
Is it common to fund a business this way in New Zealand?
Very. It is cheap, already approved and requires no application, which is exactly why the decision is frequently made by default rather than deliberately.
What is the real risk?
That a business failure reaches the family home directly, with no company between the two. The saving is real and so is the removal of the firewall, and the trade deserves to be made explicitly.
Does the interest treatment differ?
The treatment ordinarily follows the purpose the money was used for rather than the security behind it, subject to the accountant’s confirmation. Keeping business drawings in a separate split from the outset is what makes that supportable.
Should business and private drawings be separated?
Yes, and before the first drawing rather than afterwards. A separate sub-account used exclusively for business purposes turns a reconstruction exercise into a record, and it takes an afternoon to arrange.
Does the lender need to know?
Home loan facilities are approved on stated purposes, and whether business use sits within what was disclosed is a question for the lender and for a solicitor rather than an assumption. It is better asked than discovered.
Does it affect the business’s ability to borrow later?
Yes, indirectly. A business funded entirely on a home loan has no facility in its own name and no credit conduct to show, so its first business application is a first application despite years of trading.
Should a business hold a facility anyway?
There is a real argument for it. A modest facility used lightly costs a few hundred dollars a year in line fee and builds a record the business will want when it grows beyond what a home loan can support.
What does the limit reduction do?
It is what makes the product a home loan rather than a permanent facility. Without a reducing limit the loan would never be repaid, so the schedule performs the job a repayment schedule does on a table loan.
Is this guide financial advice?
No. It compares two products in general terms. This site is not a lender, a law firm, a chartered accountant or a registered financial adviser, and a decision to secure business borrowing against a home should be taken with professional advice.
Related
Keep reading
Revolving credit facility
The business meaning of the same phrase.
Read onSecured line of credit
The business facility that uses property as security.
Read onSecured against unsecured
What the security is worth, in dollars.
Read onUnsecured line of credit
The alternative that keeps the house out of it.
Read onAll eight facilities
Every revolving arrangement compared in the same shape.
Read on