Variations, Retentions and Missing Paperwork: It Is Costing You More Than You Realise
Something a little more pointed this month in our latest insights piece… you’ll be familiar with this situation, no doubt. A client looks at an invoice and says "I never agreed to that." Yikes. Or, other similar issues like retentions are due back and you’re missing the paperwork that tells you when… because paperwork. You might have a job that has gone sideways and it ends up in front of a disputes tribunal, and your entire case comes down to a text message like "yeah nah that's fine," and b*gger all else.
We've talked in past pieces about connected digital workflows and what AI agents might eventually do for your business, but we’ve yet to touch on the specifics of how getting set up with the right systems can automate some of this - and stop the burden of loose ends, bad paperwork and save you from disputes that ends up costing you money. Businesses that get burned on variations, retentions and disputes almost never get burned because of bad workmanship - it’s the bloody paperwork! Oh, it’ll get ya.
Why Variations Are Where Most Disputes Actually Start
A variation, in plain terms, is any change to the agreed scope of work and it usually happens verbally, under time pressure on site in between everything else. But, failure to document it appropriately and then down the line, that conversation means something different to each person who was in it.
Memory is just genuinely unreliable, AND whilst you might get the odd dodger, the actual chances are you and the clients might end up not on the same page because it’s a genuine misunderstanding.... But either way - all it takes is a bit of poor communication and a lack of documentation, and a minor variation could end up in a big dispute fast.
This is the entire reason variation clauses exist in standard form contracts in the first place - like in NZS3910. They almost universally require variations to be agreed and recorded before the work proceeds, in writing, with a price attached. This sometimes slips in practice, because stopping work and downing tools to draft a formal variation notice can be seem as costing more than the admin saves.
So, assuming you thing it’s fine and the work gets done on a handshake - you’re opening yourself up to a world of pain down the line.
But what if we told you, there was an easier way, young padawan?
How Wunderbuild and WorkflowMAX Take the Admin Out of Variations
This is exactly the gap job management software is built to close. In Wunderbuild, a variation can be logged on site, from a phone, in the same couple of minutes it takes to have the conversation in the first place - what changed, why, and the cost impact. It's attached directly to the job, timestamped, and sent to the client for digital sign-off before the extra work proceeds (or immediately after, if it genuinely can't wait).
WorkflowMAX works the same way from the office or project management side - variations sit against the job record, alongside the original quote, so there's never a question of what was agreed versus what's being invoiced. No more digging through text threads or trying to reconstruct a conversation from memory weeks later. The system holds the paper trail so your team doesn't have to.
That way, you’re not swearing under your breath because the variation actually gets documented at the moment it happens, while everyone's understanding of the conversation still matches. That's the single biggest factor in whether a variation dispute even gets off the ground. Pretty nifty.
Retentions: The Paperwork You Only Remember When It's Overdue
Retentions cause a different flavour of headache, but the root problem is the same one - nobody wrote it down properly, or nobody's tracking it now.
A retention is the slice of the contract sum - as a percentage - held back by the client until the defects liability period ends and any snags are sorted. Sounds simple. In practice, it's one of the most commonly mismanaged parts of a build, because the money gets held back at the start of a project and isn't due back until months, sometimes over a year, later. By the time it's due, the person who quoted the job might not even be the one chasing it, the file's buried in an inbox somewhere, and nobody's entirely sure what date it was meant to be released or against which milestone.
Worse, if you're the one holding retentions on subcontractors, the same problem runs the other way - miss a release date and you can find yourself on the wrong end of a Construction Contracts Act complaint, or a subbie who (fairly) wants their money and isn't interested in your excuse about a lost spreadsheet.
It's a tracking issue and a pain in the backside. Tracking issues are exactly what falls through the cracks when retentions live anywhere but where they’re supposed to.
Where Job Management Software Actually Earns Its Keep on Retentions
This is the less glamorous half of job management software, but arguably the more valuable one. In WorkflowMAX, retentions are calculated automatically against the job at invoicing stage, held against that specific contract, and flagged when they're due for release - so nobody's relying on a calendar reminder that got deleted or a note that got lost when someone left the business.
Wunderbuild does the same for smaller residential and renovation jobs where retentions are less commonly formalised but just as easily forgotten - the retention sits against the job from the moment it's invoiced, so releasing it later is a case of checking the system, not reconstructing history.
Either way, the point is the same: retentions shouldn't rely on somebody remembering. They should sit in the system, attached to the job, doing the remembering for you.
When a Construction Dispute Ends Up in Front of a Tribunal
Here's the bit that should really put the wind up you. If a variation or a retention dispute goes far enough, it usually ends up in front of adjudication, the Disputes Tribunal, or in a construction contract dispute more broadly. And when it does, the deciding factor is very rarely who's telling the truth about what happened on site. It's who has the paperwork.
A text message thread with a vague "yeah nah that's fine" buried somewhere in fifty other messages about drop-off times and smoko is not a paper trail is it? It’s barely anything.
Basically - if it’s not officially documented, you can’t expect it to be dated against the job, properly itemised, and - it's genuinely painful to try and present as evidence months or years after the fact - assuming you can even find it. Meanwhile, a variation that was logged, priced and digitally signed off the same day it happened is about as close to bulletproof as construction paperwork gets.
Bringing It All Together With Xero Integration
The last piece of the puzzle is making sure none of this lives in isolation. Both Wunderbuild and WorkflowMAX integrate directly with Xero, so a signed-off variation or a released retention doesn't just sit as a record on the job - it flows straight through to your invoicing and your accounts, with the same numbers, the same dates, and the same documentation trail all the way through.
That matters more than it sounds like it should. A lot of paperwork disputes don't start with two parties and their not exactly well-kept systems telling two slightly different stories, because the job file said one thing and the invoice said another, and nobody noticed - well, until someone did. When your job management and your accounting software are talking to each other, that gap closes on its own.
Variations, retentions and disputes will always be part of construction - jobs change, people forget, things get missed. But the businesses that avoid getting burned aren't the ones with better luck or better clients. They're the ones whose systems do the remembering for them.
If you want to see what that looks like for your business, get in touch with the ConTech Solutions team - we'll walk you through setting up Wunderbuild or WorkflowMAX, connected to Xero, so the paperwork stops being the thing that gets ya.
Frequently Asked Questions
What is a variation in a construction contract? A variation is any change to the original agreed scope of work on a construction project - whether that's an added task, a material swap, or a design change - along with any resulting change to cost or programme.
Do construction variations need to be in writing in NZ? Under standard form contracts like NZS3910, variations should be agreed and recorded in writing, with a price attached, before the additional work proceeds. In practice this is often skipped on site, which is exactly where disputes tend to start.
What is a retention in construction and when is it paid back? A retention is a percentage of the contract sum - typically 5 to 10 percent - withheld by the client until the defects liability period ends and any defects are remedied. Release dates and amounts should be tracked against the specific job to avoid missed payments or disputes.
What happens if I don't release a subcontractor's retention on time? Missing a retention release date can put you in breach of obligations under the Construction Contracts Act and may lead to a formal payment dispute or complaint from the subcontractor.
Can a text message be used as evidence in a construction dispute? Yes, but informal messages are weak evidence compared to a dated, itemised, signed-off record. Tribunals and adjudicators weigh clear documentation - like a logged and approved variation - far more heavily than an ambiguous text thread.
How does job management software like Wunderbuild or WorkflowMax help prevent disputes? Both platforms let you log variations on site with a timestamp, cost, and digital client sign-off, and automatically track retentions against each job - creating a clear paper trail that removes reliance on memory or scattered messages.
Does WorkflowMax or Wunderbuild integrate with Xero? Yes, both integrate directly with Xero, so signed-off variations and released retentions flow straight through to invoicing and accounts, keeping job records and financials consistent.
Variations, retentions and disputes will always be part of construction - jobs change, people forget, things get missed - but you can reduce disputes with the correct systems and job management software.
Want to know what a connected workflow looks like for your specific business — and how it sets you up for where the industry is heading?
That's exactly what we do at ConTech Solutions. No obligation, no jargon - just a straight conversation about what makes sense for where you're at. Drop us a message and let’s chat.