If you price work off what the client tells you they need, this one has caught you at some point. The job looked clear enough. They said they needed items one, two and three, you priced one, two and three, and everybody signed. Then work starts and doing those three properly turns out to need three more nobody mentioned.
How it plays out on a job
- Work begins and the real scope turns out bigger than the bid.
- You're explaining a change order for something you couldn't have priced.
- The client feels blindsided and thinks you should have caught it.
- Equipment already ordered turns out wrong for the application.
- The schedule slips waiting on a replacement with a long lead time.
Why finding out late is the expensive part
None of it was in the scope, none of it was in the price, and now you are the one explaining it. By the time the gap shows up the money and the schedule are committed, so everything still on the table is expensive. Specialty equipment can run six months to well over a year on lead time, so ordering the wrong thing doesn't mean swapping it. It means a stalled job and a difficult conversation about who pays for the wait.
The step that got skipped
The price went out before anybody had confirmed what the job actually was.
The client described the problem as they understood it, which was a fair guess and often a symptom rather than the cause. Nobody was wrong on purpose. The information just wasn't there yet, and the number went out regardless.
Without something in the process that checks the real scope before the price is committed, the gap between the assumed job and the actual one stays hidden until it costs money. It repeats from job to job because skipping it never hurts on the day you skip it.
What would have caught it
There is a phase that exists for exactly this, making the real scope visible before anybody spends money against a guess. It costs a small fraction of the project and it is the line contractors cut most often.