Ever wondered why you’re profitable on paper but broke in the bank? You feel like you’re running on a treadmill that’s slowly speeding up. You’re working harder, taking on bigger jobs, and moving more money than ever before, but the “profit” never seems to make it into your personal pocket. If this sounds familiar, you aren’t alone. You are experiencing the “Builder’s Paradox”. A financial blind spot that sinks more construction companies than bad weather or high interest rates ever could.

This isn’t an issue of bad luck. It is a structural failure to track Work in Progress Adjustments (WIP Adjustments). If you don’t understand WIP Adjustments, you don’t know your real profit. And in the 2026 construction landscape, what you don’t know won’t just hurt you, it will put you out of business!

What Are WIP Adjustments And How Are They Applied In NZ?

WIP Adjustments are a financial calculation used to align the revenue reported on your Profit and Loss statement with the actual value of work completed on-site. In the construction industry, billing usually happens in “chunks” (progress claims), but work happens continuously. WIP Adjustments essentially fix the mismatch between when you send an invoice and when you actually incur the costs to earn that money.

Two common financial scenarios that arise in construction are:

• Under-Billing: If you have done $50k worth of work but have only billed $40k, you have an asset.
• Over-Billing: If you have billed $100k but have only done $70k worth of work, you have a $30k liability.

Most builders are chronic ‘over-billers’. They front-load their contracts to stay ahead of cash flow. While this helps the bank balance, it creates a massive taxable profit on paper that hasn’t actually been earned yet.

This is why the WIP Adjustment calculation is a concept that is a crucial part of New Zealand construction accounting. If your NZ accountant isn’t performing a WIP Adjustment at the end of each month or at the end of the financial year, your profit numbers are likely incorrect, and you could be overpaying your terminal tax.

How Is The WIP Adjustment Used In New Zealand?

The accounting principle itself is a standard practice in New Zealand (known as Work in Progress Adjustment or Revenue Recognition). Aside from more accurately depicting your financials, here is how it is used specifically for NZ businesses.

• IRD Compliance: In New Zealand, the Inland Revenue Department generally requires businesses to report income based on the “accrual” method if their turnover is over a certain threshold. If you have over-billed (received more money than work completed), that money is technically a liability, not income. If you don’t adjust for this, you may end up paying more Income Tax than you should for that financial year.
• NZS 3910 And Progress Claims: Most NZ residential and commercial contracts follow standard forms like NZS 3910. These allow for progress claims. Because these claims often don’t perfectly align with the actual costs sitting in your “Cost of Goods Sold” for that month, NZ accountants use WIP adjustments to smooth the profit so your monthly reports are accurate.
• Bank Lending: If you are applying for a business loan or a line of credit with an NZ bank, they will often look at your Work in Progress schedule. They want to see if you have negative WIP (over-billed), which they view as a debt the business owes to the projects.

Why Is The WIP Adjustment Important?

To understand why so many builders struggle to remain profitable, it helps to look at the research around cash flow, salaries and WIp adjustments. The 2025 State of Residential Construction Industry (SORCI) Report recently released a set of findings that should serve as a wake-up call for most domestic builders, no matter what country they operate in. The report identified a massive performance gap between the top 10% of builders and everyone else. The differentiator wasn’t the quality of their craftsmanship; it was the frequency and accuracy of their financial reporting. Some key insights from the SORCI Report are:

• The Profitability Gap: Builders who produce and review monthly financial reports average a 6% net profit. Those who only look at their numbers quarterly or annually (usually when the accountant asks) struggle with a 4% average. That 2% difference might sound small, but on a $5M turnover, that’s an extra $100,000 in your pocket every year.
• The Salary Trap: One of the biggest mistakes builders make is treating their own “drawings” as profit. Smart builders include their own market-rate salary as a fixed expense. The data shows that builders who do this are 2.5 times more likely to maintain positive working capital.
• The WIP Adjustment Crisis: Perhaps the most shocking statistic is that only 11.4% of builders actually know how to calculate WIP Adjustment correctly. This means 88.6% of the industry is flying blind, making massive business decisions based on estimated profits that may not exist.
• The Cash Flow Trap. In almost any other industry, accounting is simple. You buy a shirt for $20, you sell it for $50, and you have $30 in profit. Construction is different. You receive a $100,000 progress payment today for work you might not finish for another three weeks. Because that money is in your bank account, it looks like profit. You use it to pay off the materials from the previous job or perhaps to put a deposit on a new company vehicle. This is what’s known as the ‘Cash Flow Trap’. You are effectively using tomorrow’s money to pay for yesterday’s problems.

Without a Work in Progress Adjustment, your Profit and Loss statement is essentially a work of fiction. It shows the money coming in and the money going out, but it fails to account for the liability of the work you still owe the client.

The Silent Killer – Paying Tax On “Fake” Profits

Imagine you have a great year. You’ve front-loaded five big projects, and your bank account is healthy. Your accountant looks at your books at the end of the financial year, they see $500,000 in the bank and a high “income” figure because you’ve billed heavily. Because you haven’t adjusted for WIP, the accountant tells you that you’ve made a $300,000 profit. They then hand you a tax bill for $75,000.

But here’s the problem: $200,000 of that profit is actually money you need to pay for the bricks, timber, and carpenters required to finish those five houses in the next financial year. You are now paying the government real cash on fake profits. This is how builders end up insolvent despite having a full pipeline of work. They literally grow themselves into bankruptcy by increasing their tax liability faster than their actual cash reserves.

Why Most Builders Avoid The Numbers

If the stakes are this high, why do 88% of builders ignore the math? It usually comes down to three common myths:

Myth 1: “I’m a builder, not a bean counter”. Many builders take pride in being on the tools or on-site. They view office work as a distraction from the “real work.” The reality is that in 2026, the real work is ensuring your business survives!

Myth 2: “My accountant handles it”. This is the most dangerous assumption. Most generalist accountants focus on. They aren’t interested in your management accounting. If your accountant isn’t asking for your project completion percentages every month, they aren’t calculating your WIP Adjustment, and they aren’t giving you a true picture of your health.

Myth 3: “If there’s money in the bank, I’m fine”. In construction, the bank balance is the least reliable indicator of health. Because of the delay between billing and expenses, you can be months away from a total collapse while still having $200k in the account.

The 5-Step Framework For Financial Control

If you want to move into that top 10% of profitable builders, you need to implement a system of Financial Governance. Here is the basic roadmap (this information is given as a guide only, always seek professional advice specific to your financial situation).

1. Carry Out A Monthly Health Check. You wouldn’t wait until a house is finished to check if the walls are level. You check them every day. Your business is no different. You must produce a Profit and Loss and a Balance Sheet every single month. These reports allow you to spot “margin creep” before it turns into a loss.
2. Implement A WIP Adjustment Process. Every month, you (or your project manager) must estimate the percentage of completion for every active job. This data is then used to adjust your income. If you’ve billed more than you’ve built, that excess money is moved to a liability account on your balance sheet. It isn’t profit; it’s a fund for future costs.
3. Track ‘True’ Net Margin. Gross margin (the difference between your contract price and your direct costs) is a vanity metric. What matters is your Net Margin, or what’s left after you pay your rent, your admin staff, your software subscriptions, and your own salary. The SORCI report proves that 6% is the benchmark.
4. Separate Your Accounts. Stop running your business out of one bucket. Create a separate Tax Holding Account. Every time a progress claim is paid, move 15-20% into that account immediately. If you can’t afford to move that money, you aren’t profitable; you’re just borrowing from the tax office.
5. Hire Construction-Specific Expertise. A generalist accountant is great for a coffee shop, but they often don’t understand the nuances of construction retention, variations, and WIP Adjustment. Work with a construction financial coach or a specialist accountant who understands the construction industry.

We know you didn’t start your building company to be a slave to a spreadsheet, but the spreadsheet is what will set you free. Let’s take the blindfold off. It’s time to calculate your true position, protect your cash flow, and build a company that is as strong financially as the homes you build on-site.