{
  "$comment": "Machine-readable companion to https://valem.run/calculators/italy/car-tax. Formula, inputs, outputs, engine-verified test vectors, cited sources and the re-runnable Valem ModelSpec behind the page.",
  "url": "https://valem.run/calculators/italy/car-tax",
  "dataUrl": "https://valem.run/calculators/italy/car-tax.json",
  "license": {
    "name": "CC BY 4.0",
    "url": "https://creativecommons.org/licenses/by/4.0/",
    "attribution": "Italy bollo auto model by Valem (https://valem.run/calculators/italy/car-tax), CC BY 4.0.",
    "note": "Covers the model — the expression of each rule and the arrangement of the catalog. The rates and thresholds themselves are law and are not licensed by anyone; the cited sources are where they come from."
  },
  "verificationUrl": "https://valem.run/calculators/italy/car-tax/verify",
  "country": "italy",
  "countryName": "Italy",
  "formula": "car-tax",
  "formulaName": "Bollo auto",
  "title": "Calcolo Bollo Auto — Italy car tax",
  "answer": "Italy's annual car tax (bollo auto) is a kW-based charge plus a superbollo surcharge on power above 185 kW.",
  "lang": "en",
  "currency": "EUR",
  "taxYear": "2026",
  "verification": {
    "claim": "internal-consistency",
    "statement": "The Valem engine reproduces this model's stated formula through 3 self-test cases (below, and re-runnable against the spec). That asserts internal consistency, NOT that the formula matches current law — the cited sources are the evidence for that, and carry the date each was last checked.",
    "selfTestCases": 3,
    "ratesAreIllustrative": false,
    "sourcesCheckedOn": "2026-08-02"
  },
  "sources": [
    {
      "label": "Calcolo bollo — ACI",
      "url": "https://www.aci.it/i-servizi/servizi-online/bollo-auto.html",
      "checked": "2026-08-02"
    }
  ],
  "terminalOutput": "total",
  "inputs": [
    {
      "name": "kw",
      "type": "number",
      "label": "Potenza (kW)",
      "minimum": 0
    },
    {
      "name": "regione",
      "type": "string",
      "label": "Regione"
    },
    {
      "name": "customFactor",
      "type": "number",
      "label": "Coefficiente se « Altra » (es. 1.00)",
      "minimum": 0.5,
      "maximum": 1.5
    }
  ],
  "outputs": [
    {
      "name": "regionFactor",
      "type": "number",
      "label": "Coefficiente regionale",
      "formula": "($r := regione; $r = 'standard' ? $const.factorStandard : $r = 'emilia' ? $const.factorEmiliaRomagna : $r = 'toscana' ? $const.factorToscana : $r = 'abruzzo' ? $const.factorAbruzzoCampania : $r = 'bolzano' ? $const.factorBolzano : customFactor)"
    },
    {
      "name": "bollo",
      "type": "number",
      "label": "Bollo",
      "format": "currency",
      "formula": "($k := kw; $b := $k <= $const.kwThreshold ? $k * $const.rateLow : $const.kwThreshold * $const.rateLow + ($k - $const.kwThreshold) * $const.rateHigh; $round($b * regionFactor, 2))"
    },
    {
      "name": "superbollo",
      "type": "number",
      "label": "Superbollo (oltre 185 kW)",
      "format": "currency",
      "formula": "$round(kw > $const.superThreshold ? (kw - $const.superThreshold) * $const.superRate : 0, 2)"
    },
    {
      "name": "total",
      "type": "number",
      "label": "Bollo annuo",
      "format": "currency",
      "formula": "$round(bollo + superbollo, 2)"
    }
  ],
  "testCases": [
    {
      "description": "C1 88 kW petrol",
      "given": {
        "kw": 88,
        "regione": "standard"
      },
      "expect": {
        "bollo": 227.04,
        "superbollo": 0,
        "total": 227.04
      }
    },
    {
      "description": "C3 200 kW — bollo plus superbollo",
      "given": {
        "kw": 200,
        "regione": "standard"
      },
      "expect": {
        "bollo": 645,
        "superbollo": 300,
        "total": 945
      }
    },
    {
      "description": "C2 88 kW immatricolata in Emilia-Romagna — +10% dal 2026",
      "given": {
        "kw": 88,
        "regione": "emilia"
      },
      "expect": {
        "regionFactor": 1.1,
        "bollo": 249.74,
        "total": 249.74
      }
    }
  ],
  "spec": {
    "id": "car-tax-italy",
    "version": "1.0.0",
    "schema": {
      "type": "object",
      "properties": {
        "kw": {
          "type": "number",
          "minimum": 0
        },
        "regione": {
          "type": "string"
        },
        "customFactor": {
          "type": "number",
          "minimum": 0.5,
          "maximum": 1.5
        },
        "regionFactor": {
          "type": "number",
          "readOnly": true
        },
        "bollo": {
          "type": "number",
          "readOnly": true
        },
        "superbollo": {
          "type": "number",
          "readOnly": true
        },
        "total": {
          "type": "number",
          "readOnly": true
        }
      }
    },
    "constants": {
      "rateLow": 2.58,
      "rateHigh": 3.87,
      "kwThreshold": 100,
      "superThreshold": 185,
      "superRate": 20,
      "factorStandard": 1,
      "factorEmiliaRomagna": 1.1,
      "factorToscana": 1.05,
      "factorAbruzzoCampania": 1.21,
      "factorBolzano": 0.76
    },
    "defaultValues": [
      {
        "path": "$",
        "expr": "{ 'kw': 88, 'regione': 'standard', 'customFactor': 1 }"
      }
    ],
    "derivations": [
      {
        "path": "$.regionFactor",
        "expr": "($r := regione; $r = 'standard' ? $const.factorStandard : $r = 'emilia' ? $const.factorEmiliaRomagna : $r = 'toscana' ? $const.factorToscana : $r = 'abruzzo' ? $const.factorAbruzzoCampania : $r = 'bolzano' ? $const.factorBolzano : customFactor)"
      },
      {
        "path": "$.bollo",
        "expr": "($k := kw; $b := $k <= $const.kwThreshold ? $k * $const.rateLow : $const.kwThreshold * $const.rateLow + ($k - $const.kwThreshold) * $const.rateHigh; $round($b * regionFactor, 2))"
      },
      {
        "path": "$.superbollo",
        "expr": "$round(kw > $const.superThreshold ? (kw - $const.superThreshold) * $const.superRate : 0, 2)"
      },
      {
        "path": "$.total",
        "expr": "$round(bollo + superbollo, 2)"
      }
    ],
    "constraints": [],
    "metaDerivations": [],
    "viewDefinition": {
      "renderer": "builtin",
      "defaultView": "main",
      "views": [
        {
          "id": "main",
          "label": "Bollo auto",
          "layout": "vertical",
          "components": [
            {
              "id": "kw",
              "type": "numericField",
              "label": "Potenza (kW)",
              "bind": "$.kw"
            },
            {
              "id": "regione",
              "type": "selectField",
              "label": "Regione",
              "bind": "$.regione",
              "helperText": "Le regioni possono variare la tariffa nazionale di circa ±10%. Scegli la tua o inserisci il tuo coefficiente.",
              "options": [
                {
                  "value": "standard",
                  "label": "Tariffa nazionale — 2,58 €/kW fino a 100 kW"
                },
                {
                  "value": "emilia",
                  "label": "Emilia-Romagna — +10% dal 1° gennaio 2026"
                },
                {
                  "value": "toscana",
                  "label": "Toscana — circa 2,71 €/kW (+5%)"
                },
                {
                  "value": "abruzzo",
                  "label": "Abruzzo e Campania — fino a 3,12 €/kW (+21%)"
                },
                {
                  "value": "bolzano",
                  "label": "Bolzano — 1,96 €/kW per Euro 6 (-24%)"
                },
                {
                  "value": "altra",
                  "label": "Altra regione — inserire il coefficiente"
                }
              ]
            },
            {
              "id": "factor",
              "type": "numericField",
              "label": "Coefficiente se « Altra » (es. 1.00)",
              "bind": "$.customFactor"
            },
            {
              "id": "tiles",
              "type": "group",
              "layout": "horizontal",
              "components": [
                {
                  "id": "totalTile",
                  "type": "statTile",
                  "label": "Bollo annuo",
                  "bind": "$.total",
                  "format": "currency",
                  "currency": "EUR"
                }
              ]
            },
            {
              "id": "breakdown",
              "type": "keyValueList",
              "label": "Dettaglio",
              "items": [
                {
                  "label": "Coefficiente regionale",
                  "bind": "$.regionFactor"
                },
                {
                  "label": "Bollo",
                  "bind": "$.bollo",
                  "format": "currency",
                  "currency": "EUR"
                },
                {
                  "label": "Superbollo (oltre 185 kW)",
                  "bind": "$.superbollo",
                  "format": "currency",
                  "currency": "EUR"
                },
                {
                  "label": "Totale",
                  "bind": "$.total",
                  "format": "currency",
                  "currency": "EUR"
                }
              ]
            },
            {
              "id": "note",
              "type": "staticText",
              "text": "'Italia: bollo auto in base ai kW, corretto per regione (±10%), circa 2,58 EUR/kW fino a 100 kW e 3,87 EUR/kW oltre, più superbollo di 20 EUR/kW oltre 185 kW. Stima, non è consulenza fiscale. Le tariffe nazionali non sono cambiate nel 2026, ma l'Emilia-Romagna ha aumentato tutte le tariffe del 10% dal 1° gennaio 2026.'"
            },
            {
              "id": "sources",
              "type": "sourceList",
              "label": "Fonti",
              "items": [
                {
                  "label": "Calcolo bollo — ACI",
                  "url": "https://www.aci.it/i-servizi/servizi-online/bollo-auto.html",
                  "date": "2026-08-02"
                }
              ]
            }
          ]
        }
      ]
    },
    "tests": [
      {
        "description": "C1 88 kW petrol",
        "given": {
          "$.kw": 88,
          "$.regione": "standard"
        },
        "expect": {
          "$.bollo": 227.04,
          "$.superbollo": 0,
          "$.total": 227.04
        }
      },
      {
        "description": "C3 200 kW — bollo plus superbollo",
        "given": {
          "$.kw": 200,
          "$.regione": "standard"
        },
        "expect": {
          "$.bollo": 645,
          "$.superbollo": 300,
          "$.total": 945
        }
      },
      {
        "description": "C2 88 kW immatricolata in Emilia-Romagna — +10% dal 2026",
        "given": {
          "$.kw": 88,
          "$.regione": "emilia"
        },
        "expect": {
          "$.regionFactor": 1.1,
          "$.bollo": 249.74,
          "$.total": 249.74
        }
      }
    ]
  }
}