The invoice went out, the customer paid, and somehow the job still barely broke even. The materials receipts know why.

Every trade business has had at least one job that looked perfectly profitable on the quote and somehow ended up barely breaking even - extra materials bought on the fly, a return trip for a part that wasn't accounted for, waste that nobody added up until it was far too late to matter.

Why materials costs are so easy to lose track of

A receipt in a van door pocket, a trade counter purchase paid for personally and half-remembered at invoicing time, an extra length of cable that never made it onto anything written down - none of it is dramatic individually, but it quietly erodes margin on jobs that looked fine on paper.

Attaching cost to the job it actually belongs to

Recording required and used materials directly against a job, and converting material use into tracked expenses, means the real cost of a job is visible before the next similar one gets quoted - not discovered, with mild horror, at year-end accounts.

The verdict

A job that "somehow" made no money usually has a very findable reason. It's just rarely written down anywhere until someone goes looking.