Invoice sample
This is a specimen. The client, the dates and the figures below are examples chosen to exercise the arithmetic, and they are not a transaction. No real invoice is reproduced here.
What an invoice carries
| Field | Example | Note |
|---|---|---|
| Number | HP-0004 | Prefix from the client, sequence per client |
| Issued | 2026-09-21 | |
| Due | 2026-10-21 | Thirty day terms |
| From | Bryan J. Calabro | |
| Billed to | Henderson Partners | An example name, not a client |
Lines
| Description | Quantity | Rate | Amount |
|---|---|---|---|
| Design, day rate | 10 | 150.00 | 1,500.00 |
| Research, day rate | 4 | 125.00 | 500.00 |
Totals
| Line | Amount |
|---|---|
| Subtotal | 2,000.00 |
| Discount, 10 percent | -200.00 |
| Taxable | 1,800.00 |
| Tax, 20 percent | 360.00 |
| Total | 2,160.00 |
The discount comes off before tax. That order is not cosmetic: applying tax first and discounting afterwards produces a different total and is wrong in almost every jurisdiction.
Numbering
Numbers increment per client, not globally. Each client carries a prefix taken from its name and its own sequence, so HP-0004 is Henderson Partners' fourth invoice regardless of how many went to anyone else.
Two reasons. A global sequence tells every client how much work you did last month, which is information they did not buy. And a per-client sequence with a gap in it is a question with an answer, where a gap in a global sequence is just noise.
Reusing a number is the one error worth blocking outright, because it is the one an accountant always finds. A number already used on another invoice is flagged on the document itself rather than on save.
How it is produced
The invoice is a page, filled in and printed through the browser's own dialog to an exact Letter or A4 page with real margins. Nothing is uploaded, there is no account, and the record lives in the browser it was written in.
The tool that produces it is being built. It is not linked here until its host verifies live.
What this specimen is for
Two things. It fixes the fields and the arithmetic before there is a real invoice to argue about, and it gives the close something concrete to point at when step 3 says "every invoice issued in the period is recorded with its number, client, amount, sent date, terms and expected pay date".