When does Quaderno need a postal code to calculate taxes?
In most countries, the billing country alone is enough to determine the correct tax rate. In some places, however, a country has regions or territories with different tax rules — and the only way to tell them apart is the postal code. Quaderno uses the postal code to detect which applies.
Countries where tax rates vary by state or province
In the United States and Canada, tax rates are set at the state or provincial level, not nationally. Quaderno uses the postal code to identify the correct state or province for every transaction.
| Country | Sub-jurisdictions identified by postal code |
|---|---|
| United States | All 50 states |
| Canada | All provinces and territories |
EU countries with special territories
Several EU member states include territories that are either outside the EU VAT area or that apply reduced VAT rates. Quaderno uses the postal code to detect whether your customer is in one of these territories and adjust the tax calculation accordingly.
| Country | Special territory | Tax treatment |
|---|---|---|
| Spain | Canary Islands, Ceuta, Melilla | Outside the EU VAT area |
| Germany | Heligoland, Büsingen am Hochrhein | Outside the EU VAT area |
| France | Overseas departments (DOM): Guadeloupe, Martinique, Réunion, French Guiana, Mayotte | Outside EU VAT area (Guyana, Mayotte) or reduced rates |
| Italy | Livigno, Campione d'Italia | Outside the EU VAT area |
| Finland | Åland Islands | Outside the EU VAT area |
| Portugal | Madeira, Azores | Reduced VAT rates |
| Greece | Aegean Islands, Mount Athos | Reduced VAT rates (Aegean Islands); outside the EU VAT area (Mount Athos) |
For more detail on France's overseas departments, see Applying VAT on services to the French DOM.
Countries where the region name is also required
In a small number of countries, a postal code alone is not always enough to identify the customer's region. Quaderno may also use the state or region field you provide.
| Country | What Quaderno uses | Why |
|---|---|---|
| India | Postal code + state name | Some postal codes span multiple states |
| United Arab Emirates | Emirate name | The UAE has no postal code system; tax must be reported per emirate |
For UAE transactions, make sure the state or region field on the customer's address contains the correct emirate name (for example, Dubai, Abu Dhabi, or Sharjah). Quaderno uses this to attribute the transaction to the right emirate for tax reporting.