Construction back-charges: how subs fight them

A back-charge is money a general contractor takes out of what they owe you, to cover a cost they say your company caused. Cleanup you left behind, damage to another trade's work, a schedule delay pinned on your crew, materials the GC supplied on your behalf. It shows up as a deduction on your payment application, and the first time most subcontractors see it is when the cheque comes in short.

Some back-charges are fair. If your crew genuinely damaged finished flooring, someone has to pay to fix it, and it is reasonable that it is you. The problem is the other kind: the vague deduction with no backup, the cleanup charge for a mess three trades made, the delay claim that ignores the two weeks you spent waiting on someone else. Those get reversed, but only if you fight them with paper, not with a phone call. Here is how a subcontractor keeps back-charges honest.

We run into this from the trade side. SubTrade was built inside Quality Gypsum Services, a commercial drywall contractor in Calgary, Alberta, and drywall sits at the end of the schedule where back-charges land hardest: by the time we are finishing, every other trade's damage is on walls we get blamed for.

When a back-charge is legitimate, and when it is not

Not every deduction is a fight worth having. Sort them before you react.

The pattern is simple. A legitimate back-charge has a cause tied to your scope, a cost you can verify, and notice that gave you a chance to fix it yourself first. A disputable one is missing at least one of those three.

The three things a valid back-charge needs

Before you owe a dollar, a back-charge should clear three bars. When one is missing, you have grounds to push back.

1. Notice, before the work was done

A proper back-charge starts with a chance to cure. The GC is supposed to tell you there is a problem and give you the opportunity to fix it yourself, which is almost always cheaper than their rate. A deduction for corrective work you were never told about, done by someone else at a marked-up cost, is the most reversible kind there is. Ask the question every time: was I given notice and a chance to fix this before someone else was paid to?

2. Documentation of the actual cost

A number is not a back-charge. The GC has to show the real cost: the invoice from the trade who did the repair, the hours, the receipts. A round figure with no backup ("$2,500 cleanup") is a starting position, not a substantiated charge. You are entitled to see what makes up the number, and a lot of soft back-charges evaporate the moment you ask for the paper behind them.

3. Proof the cause was actually yours

This is where your own records decide the outcome. If the GC cannot prove your crew caused the damage, and you can show the area was clean when you left, the charge does not stand. That is exactly why the site photos you took at completion matter more than any argument made after the fact. Our guide to jobsite photo documentation covers the completion shot that settles most damage back-charges before they start.

How to dispute a back-charge

When a deduction lands that you do not agree with, the response is procedural, not emotional. Speed and paper win these.

Respond in writing, fast

The worst thing you can do is let a back-charge sit. Silence reads as agreement, and payment timelines move whether you respond or not. Reply in writing, promptly, stating that you dispute the charge and why. A phone call everyone remembers differently is worth nothing later; a dated email is a record.

Ask for the backup

Request the substantiation: who did the work, what it cost, when, and on whose authority. Half of weak back-charges cannot survive that request because the number was never really built up in the first place.

Produce your own record

This is where a documented job pays for itself. Your completion photos, your daily logs showing when your crew was and was not on site, your notes on the condition you left the area in. Two independent, dated records, photos and a written log of the same day, are very hard for a GC to argue past. If your defence is memory, you lose. If it is timestamped documentation, you usually win.

Separate what you owe from what you dispute

If part of the charge is fair and part is not, say so, and pay or accept the fair part while disputing the rest. It keeps you credible and keeps the argument narrow. A blanket refusal of a partly valid charge just hands the GC a reason to dismiss the whole objection.

Protect yourself before the back-charge ever comes

The subcontractors who lose the least to back-charges are not better arguers. They are better documenters. Everything that wins a back-charge dispute is created before the dispute exists.

Photograph existing conditions before you start and the finished area before you leave, so damage cannot be pinned on you after the fact. Keep a daily log that records exactly when your crew was on site, because most delay back-charges collapse against a clear attendance record. Get authorization in writing before you ever let a GC supply materials on your account. And when you are directed to do extra work, capture it as a change order with a photo and a signature, so the same work does not come back later dressed up as your fault. It is worth knowing how the standard contracts handle changes and set-off; CCDC 16, the Guide to Changes in the Contract, lays out the routes a properly documented change is supposed to follow.

Back-charges also interact with the money already being held from you. A deduction stacked on top of statutory holdback can put a real dent in cash flow, and it is worth knowing exactly how much of your billing is legitimately withheld before you agree to anything more. Our construction holdback calculator shows the statutory amount by province so you can tell a lawful holdback from an opportunistic deduction.

SubTrade starts at $299/month CAD with a 14-day free trial and no credit card required, because the documentation that beats a back-charge only helps if it was captured the day the work happened, not reconstructed the day the deduction lands.

FAQ

What is a back-charge in construction?

A back-charge is a cost a general contractor deducts from what they owe a subcontractor, to recover money they say the subcontractor's actions caused, such as damage repair, cleanup, delay, or materials the GC supplied. It appears as a deduction on the payment application.

When is a back-charge legitimate?

When the cost is clearly tied to your scope, the amount is documented with real backup, and you were given notice and a chance to fix the problem yourself before someone else was paid to. If any of those three is missing, you have grounds to dispute it.

How do I dispute an improper back-charge?

Respond in writing quickly, request the substantiation behind the number, and produce your own dated records, completion photos and daily logs, that show the cause was not yours. Separate any fair portion from the disputed portion so your objection stays credible.

Can a GC back-charge me without telling me first?

For corrective work, usually not. A proper back-charge gives you notice and a chance to cure before another party does the work at a marked-up cost. A deduction for work you were never told about is often the easiest kind to reverse.

What documentation protects me from back-charges?

Photos of existing conditions and completed work, a daily log of when your crew was on site, written authorization before a GC supplies materials, and signed change orders for extra work. The record has to be created the day the work happens to hold up later.

Do back-charges affect my holdback?

They are separate deductions, but they stack. A back-charge on top of statutory holdback can strain cash flow, so confirm the lawful holdback for your province before agreeing to any additional deduction.