The extra work nobody remembers to invoice

An extra agreed with a nod on site, an hour added because the wall wasn't straight, a part swapped out in a hurry because the client needed it that same day: the work gets done, nobody disputes it, but it never shows up on an invoice. Not because anyone decided to give it away. Because three weeks later, when the invoice gets written, nobody remembers it happened.

Why agreed work goes missing#

The original quote describes what was planned. On site, a team lead agrees to a small change with a nod: "let's redo that socket while we're at it," "we need one more hour to finish it properly." The client says yes. Nobody writes anything down, because the job is to finish the site, not to fill out paperwork.

Three weeks later, the office prepares the final invoice from the signed quote. The signed quote says nothing about the socket or the extra hour. Neither does the invoice. The work had a real cost, in time and materials. It never had a price.

What a forgotten extra costs#

Take a heating contractor with around ten people, a hypothesis to show the calculation. They run about 25 jobs a month. On each one, an unplanned extra: a part, an hour, an added trip. Average value: €100 worth of work and materials, a conservative estimate.

If one extra in three is never invoiced, because it was never noted anywhere:

This isn't a discount anyone chose to grant. It's work handed to the client for free, without anyone deciding it should be.

The method: write the agreement down before leaving the site#

Four things are enough, noted on site, not at the end of the day:

1. What was done extra, in one line ("rewired the wall socket, living room").
2. An amount, even approximate. A round number beats no number at all.
3. The client's agreement, visible: a signature, or a message confirming it.
4. Sending it to the office right away, the same day, not at the end of the job.

The third point changes everything. Without a visible agreement, even a correct amount gets argued over at invoicing time: the client remembers agreeing to the work, not necessarily to the price. With a dated agreement, the invoice surprises no one.

Who captures it, who approves it, who invoices it#

Three roles, three people, so the information never stops moving:

• The team lead captures the extra on the spot, with the client right there. They're the only one who knows exactly what just happened.
• The site manager approves the amount the same day, while the job and the cost of materials are still fresh.
• The office adds the extra to the final invoice without waiting to gather everything else first.

When one person carries all three roles, or when nobody clearly owns the third one, the extra waits. And an extra that waits three weeks is an extra that never makes it onto an invoice.

What changes with an application built for the business#

The team lead logs the extra from their phone, on site: a line, an amount, a photo if needed. The client approves it with one tap, on the same screen. The information reaches the office the moment it's created, not when someone remembers to pass it on.

On the invoicing side, the extra already sits attached to the right job and the right quote by the time it's time to prepare the final invoice: nothing to dig up from a notebook, nothing to ask the team lead three weeks later.

What not to do#

Don't turn every extra minute into a billable line. An extra the client never agreed to, or one too small to justify a separate line, stays a matter of business judgment: you don't invoice everything you technically could. The method exists to stop losing what was agreed, not to price what never was.

Extra work: the key takeaways#

Work agreed on site has a price, even when it never had a quote. What makes it disappear is almost never bad faith: it's the lack of a place to note it the moment it happens, and of one person clearly responsible for passing it on.

Three roles, a written amount, a visible agreement: the final invoice then reflects what was actually done, not just what was planned a month earlier.