Discounts, tax, and totals on invoices
The order that discounts and tax usually run in, how to show each amount, and how to avoid the small math mistakes that stall payment.
By Tiny Utility Lab, the team behind FreeInvoicePDF. Updated .
Most payment delays on otherwise clean invoices come from math the client cannot follow. Subtotal, discount, tax, total. Get the order wrong by a few dollars and someone in finance will park the invoice until you explain it.
The order most clients expect
- Add the line items to get a subtotal.
- Take any discount off that subtotal.
- Calculate tax on the discounted amount.
- Show the total due.
That is the order FreeInvoicePDF uses. It matches how many small business invoices are built. Some industries do line-level tax or tax-inclusive prices. If your accountant told you to do it differently, follow them, and show every step on the PDF so the reader is not left guessing.
Subtotal
The subtotal is just quantity times rate for each line, added up. Keep line descriptions specific enough that a stranger can check them. Opaque lines like “services” invite recalculation and questions. More on writing lines in how to write an invoice.
Discounts
A discount should be visible as its own row, not buried inside a lower rate unless you agreed the rate was already discounted.
- Percentage off. Show the percent and the money amount (10% = -$316.00).
- Fixed amount off. Show the dollars removed, and say why in the notes if it was a courtesy or a negotiated cut.
- Early-pay discount. That usually lives in the payment terms (for example 2/10 net 30), not as a discount line on day one. See payment terms.
Do not silently lower a line rate and also add a discount row for the same cut. Pick one place to show it.
Tax
Whether you charge sales tax, VAT, GST, or nothing at all depends on where you are registered and what you are selling. This guide will not tell you your rate. It will tell you how to show the number once you know it.
- Put tax on its own line after the discount.
- Name the tax (for example “Sales tax 8.5%”).
- If you are not registered to collect tax, do not invent a tax line to look official.
- If some lines are taxable and some are not, say so, or split the invoice. A single blended tax that nobody can reverse-engineer will get queried.
Worked numbers
Two lines, a 10% discount, then 8.5% tax on the discounted subtotal.
| Description | Qty | Rate | Amount |
|---|---|---|---|
| Website design package | 1 | $2,400.00 | $2,400.00 |
| Copywriting (hours) | 8 | $95.00 | $760.00 |
| Subtotal | $3,160.00 | ||
| Discount (10%) | -$316.00 | ||
| Taxable amount | $2,844.00 | ||
| Sales tax (8.5%) | $241.74 | ||
| Total due | $3,085.74 | ||
Tax on the pre-discount subtotal would have been higher. That small gap is exactly what turns into a week of email. Show the discounted base before tax when both apply.
Rounding
Round money to two decimal places the same way on every invoice. If your spreadsheet rounds differently from the PDF, the client will trust neither. When a percent produces a third decimal, pick a rule and stick to it (most people round half up to the cent).
Quick checks before you send
- Line math matches quantity times rate.
- Discount is labelled and subtracted once.
- Tax rate and tax amount both appear.
- Total due is the only large bold number that matters.
- Currency symbol matches the account you want paid in.
Local tax law still wins over any internet checklist. For building the file on your own device, use the invoice generator. Ads on this site keep that generator free; there is no paywall and no payments on downloads.