If you want to generate specific tax rates and invoices for the Canary Islands, you need to ensure it is defined as a country in your Marketplace's settings.

For example:

{
     "settings": [
          {
                    "countries": {
                         "IC": {
                              "is_domestic": false,
                              "tax_number_validation": {
                                   "validation_request_timeout_ms": 45,
                                   "cache_expiry_timeout_days": 60
                              },
                              "taxation": {
                                   "services": {
                                        "service_owner_liability_rule": "consignment"
                                   },
                                   "physical": {
                                        "is_seller_registered": true,
                                        "is_physical_tax_enabled": true,
                                        "seller_tax_number": "123456"
                                   }
                              },'

After this setting is made, applicable goods that are shipped to the Canary Islands will apply the tax rate for the islands.

Address Resolution

If you send a country_code=ES-CN or you specify a Canary Island's postal code, then the service will change the country_code field to IC.