tax computation audit derived

{
  "input": {
    "body": {
      "lines": [
        {
          "base": "100.00",
          "tax_code": "STD",
          "tax_amount": "20.00",
          "description": "Consulting"
        },
        {
          "base": "100.00",
          "tax_code": "STD",
          "tax_amount": "16.67",
          "description": "Licence"
        },
        {
          "base": "80.00",
          "tax_code": "RED",
          "tax_rate": "20",
          "tax_amount": "16.00",
          "description": "Books"
        },
        {
          "base": "40.00",
          "tax_code": "OUT",
          "tax_amount": "0",
          "description": "Export"
        },
        {
          "base": "9.99",
          "tax_code": "STD",
          "tax_amount": "1.998",
          "description": "Postage"
        }
      ],
      "policy": {
        "rounding": "half_up",
        "tax_inclusive": false
      },
      "currency": "GBP",
      "schedule": [
        {
          "code": "STD",
          "rate": "20",
          "description": "standard"
        },
        {
          "code": "RED",
          "rate": "5",
          "description": "reduced"
        },
        {
          "code": "ZER",
          "rate": "0",
          "description": "zero"
        }
      ]
    },
    "type": "http",
    "method": "POST",
    "bodyType": "json"
  },
  "output": {
    "type": "json",
    "example": {
      "lines": [
        {
          "base": "100",
          "line": 1,
          "rate": "20",
          "tax_code": "STD",
          "computed_tax": "20",
          "declared_tax": "20"
        },
        {
          "base": "100",
          "line": 2,
          "rate": "20",
          "tax_code": "STD",
          "computed_tax": "20",
          "declared_tax": "16.67"
        },
        {
          "base": "80",
          "line": 3,
          "rate": "20",
          "tax_code": "RED",
          "computed_tax": "16",
          "declared_tax": "16"
        }
      ],
      "limits": {
        "maxEntries": 20000,
        "maxAccounts": 5000,
        "maxFindings": 500,
        "maxLinesPerEntry": 500,
        "maxStatementLines": 20000
      },
      "passed": false,
      "complete": false,
      "currency": "GBP",
      "findings": [
        {
          "code": "TAX_COMPUTED_UNDER_THE_OTHER_INCLUSIVITY",
          "line": 2,
          "detail": "line 2 declares 16.67, which is what 20% gives when treated as inclusive rather than exclusive. The figure is arithmetically right under the other policy, so the policy and the data disagree rather th...",
          "tax_code": "STD"
        },
        {
          "code": "RATE_DISAGREES_WITH_SCHEDULE",
          "line": 3,
          "detail": "line 3 declares 20% for RED and the schedule says 5%. One of the two is stale, and which was actually applied is only visible from the amount.",
          "tax_code": "RED"
        },
        {
          "code": "TAX_CODE_NOT_IN_SCHEDULE",
          "line": 4,
          "detail": "line 4 uses the code OUT, which the schedule does not contain. Whatever rate was applied came from somewhere this data does not show.",
          "tax_code": "OUT"
        }
      ],
      "total_tax": "58",
      "line_count": 5,
      "request_id": "example-request",
      "service_id": "tax_computation_audit",
      "total_base": "289.99",
      "assumptions": [
        "When a declared amount disagrees, the other inclusivity formula is tried as well. If that one gives the declared figure, the finding says the policy and the data disagree rather than that the arithmet...",
        "A rate on the line is used when present, and a disagreement with the schedule is reported, because which of the two was actually applied is only visible from the amount.",
        "Division is the one operation that is not exact, so the quotient is taken at four places beyond the currency minor unit and then rounded under the stated mode. Both the precision and the mode are publ..."
      ],
      "by_tax_code": [
        {
          "tax": "42",
          "base": "209.99",
          "code": "STD",
          "lines": 3
        },
        {
          "tax": "16",
          "base": "80",
          "code": "RED",
          "lines": 1
        }
      ],
      "limitations": [
        "Whether the amounts supplied follow from the rates supplied. This is not tax advice: whether a rate is correct, whether a supply is taxable, where it is taxable, and what rounding a jurisdiction requi...",
        "arithmetic_sound is true only when every rate resolved, every declared amount matched and every figure fitted the currency."
      ],
      "minor_units": 2,
      "observed_at": "2026-10-02T00:00:00.000Z",
      "not_examined": [
        "SCHEDULE_CODE_UNUSED: ZER is in the schedule and no line uses it."
      ],
      "finding_count": 5,
      "rounding_mode": "half_up",
      "tax_inclusive": false,
      "service_version": "1.0.0",
      "arithmetic_sound": false,
      "findings_by_code": {
        "TAX_AMOUNT_DISAGREES": 1,
        "TAX_AMOUNT_TOO_PRECISE": 1,
        "TAX_CODE_NOT_IN_SCHEDULE": 1,
        "RATE_DISAGREES_WITH_SCHEDULE": 1,
        "TAX_COMPUTED_UNDER_THE_OTHER_INCLUSIVITY": 1
      }
    }
  }
}