Building a package turns up payments that cannot be explained from the bank line alone. A card payment to a hardware store could be materials for a job, a tool, or something personal, and the bank record says none of that.
For those, the package asks. A receipt answers the question better than typing does.
Where it appears
While preparing a package, questions about individual payments carry a Receipt button beside the answer box. Attaching the receipt and typing an explanation both answer the question; the receipt carries more.
The button only appears on questions tied to a specific bank transaction. A general question has nothing for the receipt to attach to.
What can be attached
A photograph or a PDF. A picture taken on a phone at the counter is the common case and works.
The same advice applies as anywhere else the platform reads an image: a flat, evenly lit shot of the whole receipt reads better than one taken at an angle. Re-taking a poor photograph is usually quicker than correcting what came out of it.
What happens after
The details are read from the receipt — what was bought, from whom, for how much — and held against that transaction. The button changes to Uploaded once it has been accepted.
Why bother, when typing is faster
Typing "materials for the Henderson job" answers the question. It does not prove anything.
A receipt does. If the books are ever examined, the difference between a claim that holds and one that gets disallowed is usually whether the record exists, not whether the spending was legitimate — see record retention for how long those records need keeping.
The receipt is also the only record of what was actually on it. A card statement shows one total at a builders' merchant; the receipt shows which of those lines belonged to which job, and which was the coffee that should be marked personal.
A supplier price list is a different thing
A price list is not a receipt. It is not something bought, it is what things cost — and it belongs in the pricing catalogue rather than against a transaction. See importing supplier prices.
Who can attach one
Anyone whose role allows them to work in accounting. A role that can view but not change accounting records can see that a receipt is attached and cannot add or remove one.