Discounts feel like pure generosity until tax season reveals their second effect: every pre-tax dollar you knock off also shrinks the taxable base, which changes what you owe the state. I learned to love this, a well-structured discount is a small tax efficiency, but only after learning the ordering rules that make it legal.
The standard case: discount first, then tax the reduced amount. $1,000 minus a $200 coupon is an $800 taxable sale; at 8.25{e0bed9560a59d6d3feee569f5ae3dad3ee14a646b3fccc2d16becbf099999e03} that’s $66.00 in tax, not $82.50. Show both lines in order so the sequence is auditable. Percentage and fixed-amount seller discounts both work this way in nearly every state, because the state taxes what the customer actually paid you.
The exception that matters: manufacturer or third-party rebates, where the customer pays full price and gets money back from someone else later. Since you received the full amount, many states tax the full pre-rebate price, the rebate happens outside your transaction. Same logic for post-sale “cash back” that isn’t a price reduction at charge time. Structure promotions as immediate pre-tax discounts whenever you have the choice; the customer sees the same savings and your taxable base is honestly lower.
Buy-one-get-one and bundled pricing follow the same principle with messier arithmetic: allocate the discount across the taxable items proportionally and tax the result. Your software does this correctly if the discount is entered as a discount rather than fudged line prices, another reason to record discounts explicitly instead of editing prices.
Takeaway: seller discounts reduce the taxable base; third-party rebates usually don’t, record discounts as discounts.
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