This question starts more client arguments than any other in invoice tax, because both answers feel right and only one is legal in most states. I once had a customer insist, loudly, on the phone, that tax applied before their loyalty discount. They were wrong, but “trust me” wasn’t persuasive. Showing them the ordered lines was. Order your invoice so the answer is visible.
The rule across nearly every state: tax applies after seller discounts, because tax is levied on the actual amount the customer pays you. $1,000 with a 10{e0bed9560a59d6d3feee569f5ae3dad3ee14a646b3fccc2d16becbf099999e03} discount is a $900 sale; at 8.25{e0bed9560a59d6d3feee569f5ae3dad3ee14a646b3fccc2d16becbf099999e03} the tax is $74.25, and the $8.25 difference from taxing the full thousand is real money at volume. Percentage discounts, fixed-amount coupons, negotiated markdowns, all reduce the base the same way.
Two structures that don’t reduce the base: third-party rebates (manufacturer pays the customer back later; you received full price, so most states tax the full price) and post-transaction cash back (not a price reduction at charge time). When you control the promotion design, always prefer immediate pre-tax discounts, the customer perceives identical savings while your taxable base is honestly lower.
Formatting matters as much as law here. Discount line above, tax line below, taxable-amount line between them if your template supports it. A customer who can follow the sequence won’t dispute it; most discount fights I’ve seen were really legibility fights.
Takeaway: discount first, tax second, show the order, sequence visible is disputes prevented.
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How do you use Invoice Tax Breakdown Calculator?
Open the Invoice Tax Breakdown Calculator in your browser (Split any invoice into subtotal, tax, and total, per line item). Type or paste your input, adjust the options, and copy the result. Everything runs locally on your device with no account and nothing stored, so the three steps below take seconds even for confidential work.
- Enter your numbers into the fields. The result recalculates as you type.
- Switch any unit or option to see the updated answer instantly.
- Copy the result with the copy button, or read the summary beneath it.
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