Stop Losing Money on Unbilled Change Orders

Contractors lose an average of 9 to 13 percent of project revenue to unbilled change orders, according to data consistently cited across construction industry surveys. On a $150,000 remodel, that is $13,500 to $19,500 walking out the door. The work gets done. The bill never gets sent. And most contractors have no idea how bad the leak actually is until they look back at a closed job and wonder why the margin was so thin.

This article gives you a concrete system to capture every construction change order, price it correctly, get written approval before the work starts, and bill it before you move on. It works for a one-person shop and it scales when you add crew.

Key takeaways

• Contractors commonly lose 9-13% of project revenue to unbilled or underbilled change orders, most of it from verbal approvals that never get formalized.
• A change order is not complete until it has a scope, a price, a signature, and a billing date. Missing any one of those four things costs you money.
• The fix is not software or a new process. It is a four-step habit: document, price, approve, bill. In that order, every time.
• Scope creep is the most expensive version of this problem because the extra work feels small in the moment and enormous on the invoice.
• You can build a working contractor change order system today using a one-page template and a rule: no work starts until the change order is signed.

Why change orders bleed money before you ever pick up a tool

A change order is a written amendment to the original contract that describes new or modified work, sets a new price, and gets signed by both parties before the work begins. That definition sounds simple. The jobsite reality is not.

Here is how it actually goes. You are three weeks into a kitchen remodel. The GC calls at 7 a.m. and says the homeowner wants the island moved two feet east and the outlet count doubled. You say fine, you will handle it. You handle it. You do not write it up because the day got away from you, because the GC seemed like he would pay it, because it felt like a small thing. Three weeks later you invoice and the GC says the island relocation was "in scope" and the extra outlets were "part of the rough-in." You argue. You get paid half. Or nothing.

That is not a negotiation failure. That is a documentation failure. And it happens dozens of times a year on active jobs.

The specific ways change order billing breaks down fall into four categories, and most contractors are getting hit by all four at once.

Verbal approvals. Someone on-site says "yeah go ahead" and you treat that as a green light. It is not. A verbal approval is a handshake promise from someone who may not have authority to commit the owner's money, may not remember the conversation, or may leave the project before the invoice lands.

Scope creep. Scope creep is when the project expands gradually through small additions, each of which seems too minor to formalize. Five extra recessed lights here. An upgrade from builder-grade fixtures to mid-grade there. A second exhaust fan because the inspector flagged it. Individually, each item is a hundred or two hundred dollars. Accumulated across a six-week job, it is a $4,000 line item you never billed.

Rush decisions under pressure. A plumber hits a cast-iron stack that was not on the drawings. The GC is standing next to him saying "just deal with it, we are behind." The plumber deals with it. He does not write it up. Three extra hours of labor and $380 in materials disappear into the job cost.

Delayed billing. You capture the change order, you price it, you even get a signature. Then it sits in a folder or a text thread while you finish the job. By the time you invoice, the owner has paid the GC, the GC has closed out their draws, and your change order is a problem nobody wants to solve.

How much are you actually leaving on the table

Most contractors underestimate this number because unbilled work does not show up anywhere. It is invisible. You cannot look at a job cost report and see what you did not bill. You only see it when you reconstruct a job after the fact and compare your labor hours and material receipts to the invoices you sent.

Try this exercise on a closed job. Pull your invoices, your time cards, and your material receipts for any project over $50,000. Add up every hour of labor and every dollar of materials that did not appear on a formal invoice line. Then price those hours at your actual billing rate.

Most contractors who do this exercise find between $2,000 and $8,000 in unbilled work on a single medium-sized project. A remodeling contractor running eight to ten jobs a year could be leaving $20,000 to $60,000 on the table annually. That is not a rounding error. That is a truck payment, a helper's salary, or six months of profit margin.

The construction industry tracks this problem poorly because most of the losses happen below the radar of formal contract disputes. The Association of General Contractors has noted that change order management is one of the top sources of contractor-owner disputes, but the silent losses, the ones that never become disputes because the contractor never invoiced them in the first place, do not get counted.

Here is a rough benchmark to calibrate your own situation:

These are estimates based on the 9-13 percent loss rate applied to realistic project mixes. Your number will depend on your trade, your client mix, and how tight your current process is.

The four-step system that closes the leak

The goal here is not a complicated workflow. It is a simple rule applied consistently: no extra work starts until a signed change order exists. That rule, enforced every time, stops most of the bleeding. The four steps below are how you enforce it in practice.

Step 1: Document the change the moment it comes up

When a client or GC requests extra work, your first move is to write it down. Not when you get back to the truck. Not tonight. Right now. Even a voice memo works as a temporary capture, as long as you convert it to a written document within 24 hours.

The documentation needs four things: what the work is (specific enough that someone else could do it from the description), why it is outside the original scope, when it was requested, and who requested it. That last point matters. If the person requesting the work does not have authority to approve spending, you need to get the right person on the phone before work starts.

A kitchen remodel example: the homeowner's spouse shows up on day four and asks you to add a pot-filler outlet above the stove. That is a clear scope addition. Write it down: "10/14, homeowner (Sarah M.) requested addition of one 20-amp outlet for pot-filler above range, not included in original scope." That note takes 30 seconds. It is the difference between getting paid and eating the cost.

Step 2: Price it before you start

Pricing a change order after the work is done is always harder and always pays less. You lose the leverage of withholding work, and the client's memory of how complex the job was fades the moment the drywall is back up.

Price the change order like you price the original contract: labor hours at your full billing rate, materials at cost plus markup, any subcontractor costs with your markup, and overhead allocation if the change adds significant schedule time.

A few real numbers to anchor this:

• Adding a 20-amp kitchen circuit (rough, no fixture): $350-$600 depending on run length and access.
• Rerouting a 3-inch drain line because of an unexpected obstruction: $400-$900 in labor plus materials.
• Upgrading from standard drywall to mold-resistant in a discovered wet area: material cost difference plus $1.50-$2.50 per square foot in additional labor.
• Adding a bathroom exhaust fan not in original scope: $280-$550 installed.

If you are uncertain on the price because the scope is unclear (which happens often when you have just found something unexpected inside a wall), use a time-and-materials change order with a not-to-exceed cap. State the cap clearly. "This change order is T&M, not to exceed $1,400. Work will not exceed this amount without a revised change order." That protects you and the client.

Step 3: Get written approval before work starts

This is the rule that most contractors break under jobsite pressure. The foreman is standing there. The schedule is tight. Stopping work to get a signature feels awkward.

Do it anyway. Every time.

Written approval does not mean a formal notarized document. It means something signed or acknowledged in writing before the work starts. An email reply saying "approved, go ahead" is written approval. A text message with a photo of the change order and a thumbs-up reply is not ideal, but it is better than nothing and has held up in small claims court. A DocuSign or a PDF signature sent from the jobsite is best.

Build a standing policy and communicate it up front. Tell your clients at contract signing: "Any work outside this contract requires a written change order before it starts. It is how I protect both of us." Most clients respect this. The ones who push back on it are the ones who were planning to dispute the invoice later.

If a GC gives you pressure to start work before the change order is approved, the right answer is: "I will get started as soon as I have a signature. It takes five minutes. Let me pull it up now." That answer respects the schedule and holds your line.

Step 4: Bill it immediately, not at project close

The single biggest billing mistake contractors make is batching all their change orders into the final invoice. By that point, the client has mentally closed out the project. Every line item they do not recognize becomes a dispute. The $600 outlet and the $800 drain reroute look like mystery charges on a final bill, even if you documented them perfectly.

Bill change orders as they are completed, or at your next scheduled progress billing, whichever comes first. If you bill monthly, bill every approved and completed change order in that month's invoice. Do not let them accumulate.

A concrete rule: any change order over $500 gets its own invoice line within seven days of completion. Any change order under $500 gets billed on the next scheduled draw. No exceptions.

What a working change order template actually looks like

You do not need special software to run a functional contractor change order system. You need a template with these fields:

That last field is the one most templates leave out, and it is the one that prevents the delayed billing problem. When you fill in a billing date at approval time, you create a commitment. Put it in your calendar. Honor it.

What to do with change orders the client refuses to sign

This situation comes up. The client says "that should have been included" or "you should have known that was part of the job" or just goes quiet. Here is how to handle it.

First, send the change order in writing anyway and note that work has not started pending approval. This creates a paper trail that shows you acted professionally and gave them the chance to approve.

Second, if the work is genuinely urgent and you do a portion of it under protest, document your hours and materials in real time. Send a written notice that you are proceeding under protest and reserve your right to bill for the work. That language is important if you end up in a dispute.

Third, if the client consistently refuses to sign change orders, stop taking on additional scope. Finish the contracted work, invoice correctly, and think hard before taking another project with that client.

The most expensive thing you can do is absorb disputed change orders to "keep the relationship." You train the client to expect free upgrades, you cut your margin to zero, and you still lose the relationship eventually because the resentment builds.

Building the habit: making this stick on busy weeks

A system that works when you are slow is not a system. The real test is a week when you have three active jobs, a subcontractor who did not show, and a supplier who shorted your order. That is when the change order form does not get filled out.

The fix is friction removal. The lower the effort required to document a change order, the more often it happens.

A few approaches that work for small shops:

Keep a change order template as a PDF on your phone's home screen. Two taps and you are filling it out.

Use voice memos with a daily review habit. Every evening, review your voice memos from that day and convert any scope changes to written change orders. Ten minutes a day captures everything.

Assign one person to own change orders if you have a foreman or office admin. Give them the authority to generate and track change orders. They become the system's enforcer so you do not have to remember in the middle of a busy day.

If you use any kind of field software, build change order creation into your daily close-out habit. The end of the workday does not end until any new scope changes are documented.

Frequently asked questions

Can a text message count as change order approval?

A text message can serve as written approval in a dispute, but it is weak documentation compared to a signed document. If you accept text approval, reply to the client's message with a clear summary: "Confirming your approval to add X for $Y as Change Order 003. Work will begin [date]." That reply creates a paper trail and removes ambiguity. For anything over $500, push for a proper signature. For smaller items, a clear text thread is better than nothing.

What if the GC tells me to just do the work and sort it out later?

Do not do it. "Sort it out later" is how $3,000 in extra work becomes a $900 argument at job close. If a GC is pressuring you to skip the change order, the professional response is: "I can have the change order to you in ten minutes. I need a signature before I start." If the GC cannot produce a signature and the work is genuinely time-critical, document your decision to proceed in writing and send it to the GC by email or text. That note, stating you are proceeding at their verbal direction, protects you in a dispute even without a signed CO.

How do I handle change orders when I am a sub working under a GC?

Your change order goes to the GC, not the owner. The GC then passes it up to the owner. You do not control what happens above your contract, but you control what happens in your contract. Send your change orders to the GC the same way you would send them to an owner: written, priced, and requiring a signature before work starts. Track your own change orders regardless of whether the GC has resolved them with the owner. Your contract is with the GC.

Should I mark up materials on a change order, or just pass them through at cost?

Mark them up. You are buying, delivering, staging, and standing behind those materials. A standard material markup for change orders is 15-25 percent depending on your trade, region, and the size of the material cost. Change orders should carry at least the same markup as your original contract. Many experienced contractors charge a slightly higher markup on change orders because the procurement is rushed and outside the planned buying schedule. There is nothing wrong with that. Disclose your markup rate upfront in your contract terms.

What happens if I forget to bill a change order until after the final invoice?

Send it anyway, as a separate supplemental invoice, with a clear reference to the approved change order number and date. If the change order was properly approved in writing, the billing date is a paperwork issue, not a legitimacy issue. The client approved the work and the price. Keep the invoice professional, reference the approval documentation, and do not apologize for the late billing. If the client disputes it on the grounds that you billed too late, check your state's statute of limitations for contract claims. In most states, you have years, not weeks.

How do I price a change order when I do not know what I will find inside the wall?

Use a time-and-materials change order with a not-to-exceed amount. Estimate the worst-case scenario, set the cap there, and bill actual hours and materials with your standard rates and markup. State clearly in the change order that the final amount will be actual T&M not to exceed the cap, and that any work beyond the cap requires a new approved change order. This structure protects you from scope that grows during the work and gives the client a ceiling they can budget against.

Do I need a lawyer to write a solid change order template?

No. A clear, one-page template with the fields listed in this article is legally sufficient in most states. What matters more than legal language is specificity and completeness. The description of work needs to be clear enough that a judge with no construction knowledge could understand what you did. The pricing needs to be itemized. The signatures need to be present. If you are working on projects over $500,000 or in a state with specific contractor licensing requirements, a one-time review with a construction attorney to confirm your template is worth a few hundred dollars.

Closing

Unbilled change orders are not a client problem. They are a systems problem. Most contractors who tighten up their change order billing process see an immediate improvement in job margins, not because they raised their prices, but because they finally collected what they had already earned. The work was done. The money was owed. It just never got invoiced.

Building that habit, document, price, approve, bill, gets easier when your paperwork tools are as fast as the work itself. Krue was built for exactly this kind of situation: contractors who need to capture scope, price work, and send invoices from the field without slowing down the job. If change order billing is where your margin is leaking, it is worth seeing how Krue handles it.