Materials billing generates more client friction per dollar than anything else in property services, and the cause is almost never the amount. It is that the client cannot see what they are paying for without asking.
The usual shape of the problem
A caretaker buys a replacement part, a bag of ice-melt, a filter. The receipt goes in a pocket, then a glovebox, then possibly a photo on a phone. At month-end, the amounts are transcribed onto an invoice as a line reading "materials" with a total.
The client sees one number. If they want detail, they email and ask, and someone spends twenty minutes finding receipts for a purchase made five weeks earlier. Sometimes the receipt cannot be found at all, and the provider either absorbs the cost or bills it without evidence.
Neither outcome is good. Absorbing it erodes margin invisibly. Billing without evidence erodes trust the first time the client asks.
The structural fix
Capture the receipt at the moment of the purchase, attached to the specific item it pays for.
In MapleConcierge, a service report carries a repeating extra-items section. Each row is one purchase or one piece of additional work, and each row can carry its own uploaded receipt image. The caretaker photographs the receipt standing at the counter, attaches it to the row, and moves on.
When the report is submitted, the extra items become invoice lines and the receipts travel with them. The client sees a described line with the underlying document behind it.
Why per-row matters more than it sounds
Attaching receipts to the report as a whole, or to the invoice as a whole, seems equivalent and is not.
A report with five purchases and five loose attachments requires the reader to match documents to lines themselves. If one line is queried, nobody can say with certainty which of the five receipts supports it. The evidence exists but is not addressable.
Per-row attachment means a query about one line resolves to one document. That turns a twenty-minute search into a click, and it makes the "which one is this?" conversation disappear entirely.
The markup question
Materials are typically billed at cost plus a percentage, and this is where transparency pays for itself.
Showing the receipt means showing the actual cost, which means the markup is visible. Some providers find that uncomfortable and prefer a single blended figure. The instinct is understandable and backwards.
A client who can see cost plus a contracted percentage sees a provider operating exactly as the agreement says. A client who sees only a total assumes the worst available explanation, because that is what people do with numbers they cannot check. The transparency is what makes the markup defensible.
For this to hold, the markup percentage has to come from the client's own agreement rather than a company default, and it has to be captured on the invoice at the time it was applied. A rate change next year should not silently reprice last year's line.
What it does for you, not just the client
The evidence trail has a second beneficiary. Materials purchased and never billed is one of the most common quiet margin leaks in small operations, because the receipt is the only record and the receipt is in a glovebox.
A purchase captured on the report at the moment it happens gets billed, because the report is what generates the invoice. The receipt is not just proof for the client. It is the mechanism that makes sure the cost is recovered at all.