The change order that saves the end of a job

The contract was clear, the client was happy, and yet the final invoice is being argued over. Almost always for the same reason: something changed along the way and nobody wrote it down.

What happens without one

You tear off the old roofing and four sheets of plywood are rotten. You replace them — obviously, the roof has to sit on something. You mention it in passing to the client, who nods.

On the final invoice you add $437. Half of clients pay without a word. The other half remembers the number they signed, feels cheated, and that half is the one that writes reviews.

The problem is not the amount. It is that the client signed $19,682 and is being asked for $20,119 without having signed anything in between.

What a change order does

A change order is a separate document with its own amount, its own description and its own signature. It updates the contract total, and the client always knows where they stand.

Change order no. 2 — Replacement of rotten roof sheathing (photos attached) 4 sheets · $380.00 HST 15% · $57.00 Change order total: $437.00 New contract total: $20,119.25

That document takes two minutes to produce and it settles the conversation before it happens. "New contract total" is the most important line on it: that is the one the client is looking for.

Photos do half the work

A change order for hidden work — under cladding, behind a wall, under a slab — is defended with a photo. Taken at the time, before closing it back up.

It is also why exclusions belong in the original quote: "plywood is not included and would be billed at $95 per sheet with a photo" turns a surprise change order into a promise kept.

The negative change order nobody thinks of

The client decides against the chimney flashing after all? Issue a change order with a negative amount — a $425 credit — and a new contract total.

Producing a document to reduce your own invoice feels counterintuitive. It is one of the strongest trust-building moves available: it shows the contract follows the real work in both directions, and it heads off the "you charged me for the flashing" conversation six months later.

When to issue it

Before doing the work, when you can. Right after, when you could not — a water leak does not wait for you.

What you should never do is stack up the changes and settle everything at the end. Three small change orders signed as you go pass without friction; the same total discovered on the final invoice looks like padding.