# The rule that always rounds down

Indiana requires cash payments of state and local taxes to round down. It is a narrow provision about paying tax, not a retail rule.

**Net effect: -2.600¢ per transaction, or -$26.00 per thousand cash sales, slightly favouring the customer. That is a property of the final digits of these 10 particular prices, not of the rounding rule, and it disappears if the price list or the tax rate changes. It is not a strategy.**

| | |
| --- | --- |
| Rule | always-down |
| Tax rate | 7% |
| Transactions | 10 |
| Mean delta per transaction | -2.6¢ |
| Per 1,000 cash sales | -$26.00 |
| Rounded up / down / unchanged | 0 / 8 / 2 |

## Every price

| Price | Exact total | Due in cash | Delta |
| --- | --- | --- | --- |
| $0.99 | $1.06 | $1.05 | -1¢ |
| $1.49 | $1.59 | $1.55 | -4¢ |
| $2.99 | $3.20 | $3.20 | 0¢ |
| $4.99 | $5.34 | $5.30 | -4¢ |
| $7.49 | $8.01 | $8.00 | -1¢ |
| $9.99 | $10.69 | $10.65 | -4¢ |
| $12.99 | $13.90 | $13.90 | 0¢ |
| $19.99 | $21.39 | $21.35 | -4¢ |
| $24.99 | $26.74 | $26.70 | -4¢ |
| $49.99 | $53.49 | $53.45 | -4¢ |

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Canonical URL: https://penny-rounding.gumballtools.com/rounding/tax-payments-that-round-down
JSON API: `GET https://penny-rounding.gumballtools.com/api/v1/settle?subtotal=19.99&taxRatePercent=8.25`
MCP endpoint: `https://penny-rounding.gumballtools.com/api/mcp`