diff --git a/CHANGELOG.md b/CHANGELOG.md
index c2aeea31..2f87c4e7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,7 +9,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/) and this p
 ### Added
 
 - `ae`: added UAE regime
-- `br`: supplier extensions, validations & identities
+- `br-nfse-v1`: new extensions, validations & identities for the typical service note and supplier.
 
 ## [v0.205.1] - 2024-11-19
 
diff --git a/addons/br/nfse/extensions.go b/addons/br/nfse/extensions.go
index 5edd2598..4dbe1faa 100644
--- a/addons/br/nfse/extensions.go
+++ b/addons/br/nfse/extensions.go
@@ -12,14 +12,33 @@ import (
 // of these extensions are common, they can be moved to the regime or to a
 // shared addon.
 const (
+	ExtKeyCNAE            = "br-nfse-cnae"
 	ExtKeyFiscalIncentive = "br-nfse-fiscal-incentive"
+	ExtKeyISSLiability    = "br-nfse-iss-liability"
 	ExtKeyMunicipality    = "br-nfse-municipality"
 	ExtKeyService         = "br-nfse-service"
-	ExtKeySimplesNacional = "br-nfse-simples-nacional"
+	ExtKeySimples         = "br-nfse-simples"
 	ExtKeySpecialRegime   = "br-nfse-special-regime"
 )
 
 var extensions = []*cbc.KeyDefinition{
+	{
+		Key: ExtKeyCNAE,
+		Name: i18n.String{
+			i18n.EN: "CNAE code",
+			i18n.PT: "Código CNAE",
+		},
+		Desc: i18n.String{
+			i18n.EN: here.Doc(`
+				The CNAE (National Classification of Economic Activities) code for a service.
+
+				List of codes from the IBGE (Brazilian Institute of Geography and Statistics):
+
+				* https://www.ibge.gov.br/en/statistics/technical-documents/statistical-lists-and-classifications/17245-national-classification-of-economic-activities.html
+			`),
+		},
+		Pattern: `^\d{2}[\s\.\-\/]?\d{2}[\s\.\-\/]?\d[\s\.\-\/]?\d{2}$`,
+	},
 	{
 		Key: ExtKeyFiscalIncentive,
 		Name: i18n.String{
@@ -46,12 +65,81 @@ var extensions = []*cbc.KeyDefinition{
 			i18n.EN: here.Doc(`
 				Indicates whether a party benefits from a fiscal incentive.
 
-				List of codes taken from the national NFSe standard:
-				https://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download
+				List of codes from the national NFSe ABRASF (v2.04) model:
+
+				* https://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download
 				(Section 10.2, Field B-68)
 			`),
 		},
 	},
+	{
+		Key: ExtKeyISSLiability,
+		Name: i18n.String{
+			i18n.EN: "ISS Liability",
+			i18n.PT: "Exigibilidade ISS",
+		},
+		Values: []*cbc.ValueDefinition{
+			{
+				Value: "1",
+				Name: i18n.String{
+					i18n.EN: "Liable",
+					i18n.PT: "Exigível",
+				},
+			},
+			{
+				Value: "2",
+				Name: i18n.String{
+					i18n.EN: "Not subject",
+					i18n.PT: "Não incidência",
+				},
+			},
+			{
+				Value: "3",
+				Name: i18n.String{
+					i18n.EN: "Exempt",
+					i18n.PT: "Isenção",
+				},
+			},
+			{
+				Value: "4",
+				Name: i18n.String{
+					i18n.EN: "Export",
+					i18n.PT: "Exportação",
+				},
+			},
+			{
+				Value: "5",
+				Name: i18n.String{
+					i18n.EN: "Immune",
+					i18n.PT: "Imunidade",
+				},
+			},
+			{
+				Value: "6",
+				Name: i18n.String{
+					i18n.EN: "Suspended Judicially",
+					i18n.PT: "Suspensa por Decisão Judicial",
+				},
+			},
+			{
+				Value: "7",
+				Name: i18n.String{
+					i18n.EN: "Suspended Administratively",
+					i18n.PT: "Suspensa por Processo Administrativo",
+				},
+			},
+		},
+		Desc: i18n.String{
+			i18n.EN: here.Doc(`
+				Indicates the ISS liability status, i.e., whether the ISS tax is due or not and why.
+
+				List of codes from the national NFSe ABRASF (v2.04) model:
+
+				* https://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download
+				(Section 10.2, Field B-38)
+			`),
+		},
+	},
 	{
 		Key: ExtKeyMunicipality,
 		Name: i18n.String{
@@ -63,7 +151,7 @@ var extensions = []*cbc.KeyDefinition{
 				The municipality code as defined by the IGBE (Brazilian Institute of Geography and
 				Statistics).
 
-				For further details on the list of possible codes, see:
+				List of codes from the IGBE:
 
 				* https://www.ibge.gov.br/explica/codigos-dos-municipios.php
 			`),
@@ -88,9 +176,9 @@ var extensions = []*cbc.KeyDefinition{
 		},
 	},
 	{
-		Key: ExtKeySimplesNacional,
+		Key: ExtKeySimples,
 		Name: i18n.String{
-			i18n.EN: "Opting for “Simples Nacional”",
+			i18n.EN: "Opting for “Simples Nacional” regime",
 			i18n.PT: "Optante pelo Simples Nacional",
 		},
 		Values: []*cbc.ValueDefinition{
@@ -111,10 +199,13 @@ var extensions = []*cbc.KeyDefinition{
 		},
 		Desc: i18n.String{
 			i18n.EN: here.Doc(`
-				Indicates whether a party is opting for the “Simples Nacional” tax regime.
+				Indicates whether a party is opting for the “Simples Nacional” (Regime Especial
+				Unificado de Arrecadação de Tributos e Contribuições devidos pelas Microempresas e
+				Empresas de Pequeno Porte) tax regime
+
+				List of codes from the national NFSe ABRASF (v2.04) model:
 
-				List of codes taken from the national NFSe standard:
-				https://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download
+				* https://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download
 				(Section 10.2, Field B-67)
 			`),
 		},
@@ -171,10 +262,11 @@ var extensions = []*cbc.KeyDefinition{
 		},
 		Desc: i18n.String{
 			i18n.EN: here.Doc(`
-				Indicates a special tax regime that the party is subject to.
+				Indicates a special tax regime that a party is subject to.
+
+				List of codes from the national NFSe ABRASF (v2.04) model:
 
-				List of codes taken from the national NFSe standard:
-				https://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download
+				* https://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download
 				(Section 10.2, Field B-66)
 			`),
 		},
diff --git a/addons/br/nfse/invoices.go b/addons/br/nfse/invoices.go
index ec4946a6..04e2ffcf 100644
--- a/addons/br/nfse/invoices.go
+++ b/addons/br/nfse/invoices.go
@@ -1,6 +1,8 @@
 package nfse
 
 import (
+	"regexp"
+
 	"github.com/invopop/gobl/bill"
 	"github.com/invopop/gobl/org"
 	"github.com/invopop/gobl/tax"
@@ -12,12 +14,19 @@ const (
 	FiscalIncentiveDefault = "2" // No incentiva
 )
 
+var (
+	// CodeRegexp is the regular expression used to validate the invoice code
+	CodeRegexp = regexp.MustCompile(`^[1-9][0-9]*$`)
+)
+
 func validateInvoice(inv *bill.Invoice) error {
 	if inv == nil {
 		return nil
 	}
 
 	return validation.ValidateStruct(inv,
+		validation.Field(&inv.Series, validation.Required),
+		validation.Field(&inv.Code, validation.Match(CodeRegexp)),
 		validation.Field(&inv.Supplier,
 			validation.By(validateSupplier),
 			validation.Skip,
@@ -60,7 +69,7 @@ func validateSupplier(value interface{}) error {
 		),
 		validation.Field(&obj.Ext,
 			tax.ExtensionsRequires(
-				ExtKeySimplesNacional,
+				ExtKeySimples,
 				ExtKeyMunicipality,
 				ExtKeyFiscalIncentive,
 			),
diff --git a/addons/br/nfse/invoices_test.go b/addons/br/nfse/invoices_test.go
index 222097bd..050e5984 100644
--- a/addons/br/nfse/invoices_test.go
+++ b/addons/br/nfse/invoices_test.go
@@ -19,12 +19,40 @@ func TestInvoicesValidation(t *testing.T) {
 	}{
 		{
 			name: "valid invoice",
-			inv:  &bill.Invoice{},
+			inv: &bill.Invoice{
+				Series: "SAMPLE",
+			},
 		},
 		{
 			name: "nil invoice",
 			inv:  nil,
 		},
+		{
+			name: "missing series",
+			inv:  &bill.Invoice{},
+			err:  "series: cannot be blank",
+		},
+		{
+			name: "invalid code (non-digits)",
+			inv: &bill.Invoice{
+				Code: "ABC-123",
+			},
+			err: "code: must be in a valid format",
+		},
+		{
+			name: "invalid code (padding zeroes)",
+			inv: &bill.Invoice{
+				Code: "000123",
+			},
+			err: "code: must be in a valid format",
+		},
+		{
+			name: "valid code",
+			inv: &bill.Invoice{
+				Series: "SAMPLE",
+				Code:   "123000",
+			},
+		},
 		{
 			name: "charges present",
 			inv: &bill.Invoice{
@@ -34,7 +62,7 @@ func TestInvoicesValidation(t *testing.T) {
 					},
 				},
 			},
-			err: "charges: not supported by nfse.",
+			err: "charges: not supported by nfse",
 		},
 		{
 			name: "discounts present",
@@ -45,7 +73,12 @@ func TestInvoicesValidation(t *testing.T) {
 					},
 				},
 			},
-			err: "discounts: not supported by nfse.",
+			err: "discounts: not supported by nfse",
+		},
+		{
+			name: "series missing",
+			inv:  &bill.Invoice{},
+			err:  "series: cannot be blank",
 		},
 	}
 
@@ -54,7 +87,9 @@ func TestInvoicesValidation(t *testing.T) {
 		t.Run(ts.name, func(t *testing.T) {
 			err := addon.Validator(ts.inv)
 			if ts.err == "" {
-				assert.NoError(t, err)
+				if err != nil {
+					assert.NotContains(t, err.Error(), ts.err)
+				}
 			} else {
 				if assert.Error(t, err) {
 					assert.Contains(t, err.Error(), ts.err)
@@ -172,19 +207,19 @@ func TestSuppliersValidation(t *testing.T) {
 		}
 		err := addon.Validator(inv)
 		if assert.Error(t, err) {
-			assert.Contains(t, err.Error(), "br-nfse-simples-nacional: required")
+			assert.Contains(t, err.Error(), "br-nfse-simples: required")
 			assert.Contains(t, err.Error(), "br-nfse-municipality: required")
 			assert.Contains(t, err.Error(), "br-nfse-fiscal-incentive: required")
 		}
 
 		sup.Ext = tax.Extensions{
-			nfse.ExtKeySimplesNacional: "1",
+			nfse.ExtKeySimples:         "1",
 			nfse.ExtKeyMunicipality:    "12345678",
 			nfse.ExtKeyFiscalIncentive: "2",
 		}
 		err = addon.Validator(inv)
 		if assert.Error(t, err) {
-			assert.NotContains(t, err.Error(), "br-nfse-simples-nacional: required")
+			assert.NotContains(t, err.Error(), "br-nfse-simples: required")
 			assert.NotContains(t, err.Error(), "br-nfse-municipality: required")
 			assert.NotContains(t, err.Error(), "br-nfse-fiscal-incentive: required")
 		}
diff --git a/addons/br/nfse/nfse.go b/addons/br/nfse/nfse.go
index 4497e0bc..fe4c1727 100644
--- a/addons/br/nfse/nfse.go
+++ b/addons/br/nfse/nfse.go
@@ -40,6 +40,8 @@ func validate(doc any) error {
 		return validateLine(obj)
 	case *org.Item:
 		return validateItem(obj)
+	case *tax.Combo:
+		return validateTaxCombo(obj)
 	}
 	return nil
 }
@@ -48,5 +50,7 @@ func normalize(doc any) {
 	switch obj := doc.(type) {
 	case *bill.Invoice:
 		normalizeSupplier(obj.Supplier)
+	case *tax.Combo:
+		normalizeTaxCombo(obj)
 	}
 }
diff --git a/addons/br/nfse/tax_combo.go b/addons/br/nfse/tax_combo.go
new file mode 100644
index 00000000..2879c08d
--- /dev/null
+++ b/addons/br/nfse/tax_combo.go
@@ -0,0 +1,35 @@
+package nfse
+
+import (
+	"github.com/invopop/gobl/regimes/br"
+	"github.com/invopop/gobl/tax"
+	"github.com/invopop/validation"
+)
+
+const (
+	// ISSLiabilityDefault is the default value for the ISS liability extension
+	ISSLiabilityDefault = "1" // Liable
+)
+
+func validateTaxCombo(tc *tax.Combo) error {
+	return validation.ValidateStruct(tc,
+		validation.Field(&tc.Ext,
+			validation.When(tc.Category == br.TaxCategoryISS,
+				tax.ExtensionsRequires(ExtKeyISSLiability),
+			),
+		),
+	)
+}
+
+func normalizeTaxCombo(tc *tax.Combo) {
+	if tc == nil || tc.Category != br.TaxCategoryISS {
+		return
+	}
+
+	if !tc.Ext.Has(ExtKeyISSLiability) {
+		if tc.Ext == nil {
+			tc.Ext = make(tax.Extensions)
+		}
+		tc.Ext[ExtKeyISSLiability] = ISSLiabilityDefault
+	}
+}
diff --git a/addons/br/nfse/tax_combo_test.go b/addons/br/nfse/tax_combo_test.go
new file mode 100644
index 00000000..86e6b982
--- /dev/null
+++ b/addons/br/nfse/tax_combo_test.go
@@ -0,0 +1,105 @@
+package nfse_test
+
+import (
+	"testing"
+
+	"github.com/invopop/gobl/addons/br/nfse"
+	"github.com/invopop/gobl/regimes/br"
+	"github.com/invopop/gobl/tax"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTaxComboValidation(t *testing.T) {
+	addon := tax.AddonForKey(nfse.V1)
+
+	tests := []struct {
+		name string
+		tc   *tax.Combo
+		err  string
+	}{
+		{
+			name: "valid ISS tax combo",
+			tc: &tax.Combo{
+				Category: br.TaxCategoryISS,
+				Ext: tax.Extensions{
+					nfse.ExtKeyISSLiability: "1",
+				},
+			},
+		},
+		{
+			name: "valid non-ISS tax combo",
+			tc: &tax.Combo{
+				Category: br.TaxCategoryPIS,
+			},
+		},
+		{
+			name: "missing ISS liability",
+			tc: &tax.Combo{
+				Category: br.TaxCategoryISS,
+			},
+			err: "br-nfse-iss-liability: required",
+		},
+	}
+	for _, ts := range tests {
+		t.Run(ts.name, func(t *testing.T) {
+			err := addon.Validator(ts.tc)
+			if ts.err == "" {
+				assert.NoError(t, err)
+			} else {
+				if assert.Error(t, err) {
+					assert.ErrorContains(t, err, ts.err)
+				}
+			}
+		})
+	}
+}
+
+func TestTaxComboNormalization(t *testing.T) {
+	addon := tax.AddonForKey(nfse.V1)
+
+	tests := []struct {
+		name string
+		tc   *tax.Combo
+		out  tax.ExtValue
+	}{
+		{
+			name: "no tax combo",
+			tc:   nil,
+		},
+		{
+			name: "sets default ISS liability",
+			tc: &tax.Combo{
+				Category: br.TaxCategoryISS,
+			},
+			out: "1",
+		},
+		{
+			name: "does not override ISS liability",
+			tc: &tax.Combo{
+				Category: br.TaxCategoryISS,
+				Ext: tax.Extensions{
+					nfse.ExtKeyISSLiability: "2",
+				},
+			},
+			out: "2",
+		},
+		{
+			name: "non-ISS tax combo",
+			tc: &tax.Combo{
+				Category: br.TaxCategoryPIS,
+			},
+		},
+	}
+	for _, ts := range tests {
+		t.Run(ts.name, func(t *testing.T) {
+			addon.Normalizer(ts.tc)
+			if ts.tc == nil {
+				assert.Nil(t, ts.tc)
+			} else {
+				assert.NotNil(t, ts.tc)
+				assert.Equal(t, ts.out, ts.tc.Ext[nfse.ExtKeyISSLiability])
+			}
+		})
+	}
+
+}
diff --git a/data/addons/br-nfse-v1.json b/data/addons/br-nfse-v1.json
index 062f8285..6d9ad191 100644
--- a/data/addons/br-nfse-v1.json
+++ b/data/addons/br-nfse-v1.json
@@ -5,6 +5,17 @@
     "en": "Brazil NFS-e 1.X"
   },
   "extensions": [
+    {
+      "key": "br-nfse-cnae",
+      "name": {
+        "en": "CNAE code",
+        "pt": "Código CNAE"
+      },
+      "desc": {
+        "en": "The CNAE (National Classification of Economic Activities) code for a service.\n\nList of codes from the IBGE (Brazilian Institute of Geography and Statistics):\n\n* https://www.ibge.gov.br/en/statistics/technical-documents/statistical-lists-and-classifications/17245-national-classification-of-economic-activities.html"
+      },
+      "pattern": "^\\d{2}[\\s\\.\\-\\/]?\\d{2}[\\s\\.\\-\\/]?\\d[\\s\\.\\-\\/]?\\d{2}$"
+    },
     {
       "key": "br-nfse-fiscal-incentive",
       "name": {
@@ -12,7 +23,7 @@
         "pt": "Incentivo Fiscal"
       },
       "desc": {
-        "en": "Indicates whether a party benefits from a fiscal incentive.\n\nList of codes taken from the national NFSe standard:\nhttps://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download\n(Section 10.2, Field B-68)"
+        "en": "Indicates whether a party benefits from a fiscal incentive.\n\nList of codes from the national NFSe ABRASF (v2.04) model:\n\n* https://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download\n(Section 10.2, Field B-68)"
       },
       "values": [
         {
@@ -31,6 +42,67 @@
         }
       ]
     },
+    {
+      "key": "br-nfse-iss-liability",
+      "name": {
+        "en": "ISS Liability",
+        "pt": "Exigibilidade ISS"
+      },
+      "desc": {
+        "en": "Indicates the ISS liability status, i.e., whether the ISS tax is due or not and why.\n\nList of codes from the national NFSe ABRASF (v2.04) model:\n\n* https://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download\n(Section 10.2, Field B-38)"
+      },
+      "values": [
+        {
+          "value": "1",
+          "name": {
+            "en": "Liable",
+            "pt": "Exigível"
+          }
+        },
+        {
+          "value": "2",
+          "name": {
+            "en": "Not subject",
+            "pt": "Não incidência"
+          }
+        },
+        {
+          "value": "3",
+          "name": {
+            "en": "Exempt",
+            "pt": "Isenção"
+          }
+        },
+        {
+          "value": "4",
+          "name": {
+            "en": "Export",
+            "pt": "Exportação"
+          }
+        },
+        {
+          "value": "5",
+          "name": {
+            "en": "Immune",
+            "pt": "Imunidade"
+          }
+        },
+        {
+          "value": "6",
+          "name": {
+            "en": "Suspended Judicially",
+            "pt": "Suspensa por Decisão Judicial"
+          }
+        },
+        {
+          "value": "7",
+          "name": {
+            "en": "Suspended Administratively",
+            "pt": "Suspensa por Processo Administrativo"
+          }
+        }
+      ]
+    },
     {
       "key": "br-nfse-municipality",
       "name": {
@@ -38,7 +110,7 @@
         "pt": "Código do Município do IBGE"
       },
       "desc": {
-        "en": "The municipality code as defined by the IGBE (Brazilian Institute of Geography and\nStatistics).\n\nFor further details on the list of possible codes, see:\n\n* https://www.ibge.gov.br/explica/codigos-dos-municipios.php"
+        "en": "The municipality code as defined by the IGBE (Brazilian Institute of Geography and\nStatistics).\n\nList of codes from the IGBE:\n\n* https://www.ibge.gov.br/explica/codigos-dos-municipios.php"
       },
       "pattern": "^\\d{7}$"
     },
@@ -53,13 +125,13 @@
       }
     },
     {
-      "key": "br-nfse-simples-nacional",
+      "key": "br-nfse-simples",
       "name": {
-        "en": "Opting for “Simples Nacional”",
+        "en": "Opting for “Simples Nacional” regime",
         "pt": "Optante pelo Simples Nacional"
       },
       "desc": {
-        "en": "Indicates whether a party is opting for the “Simples Nacional” tax regime.\n\nList of codes taken from the national NFSe standard:\nhttps://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download\n(Section 10.2, Field B-67)"
+        "en": "Indicates whether a party is opting for the “Simples Nacional” (Regime Especial\nUnificado de Arrecadação de Tributos e Contribuições devidos pelas Microempresas e\nEmpresas de Pequeno Porte) tax regime\n\nList of codes from the national NFSe ABRASF (v2.04) model:\n\n* https://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download\n(Section 10.2, Field B-67)"
       },
       "values": [
         {
@@ -85,7 +157,7 @@
         "pt": "Regime Especial de Tributação"
       },
       "desc": {
-        "en": "Indicates a special tax regime that the party is subject to.\n\nList of codes taken from the national NFSe standard:\nhttps://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download\n(Section 10.2, Field B-66)"
+        "en": "Indicates a special tax regime that a party is subject to.\n\nList of codes from the national NFSe ABRASF (v2.04) model:\n\n* https://abrasf.org.br/biblioteca/arquivos-publicos/nfs-e-manual-de-orientacao-do-contribuinte-2-04/download\n(Section 10.2, Field B-66)"
       },
       "values": [
         {
diff --git a/examples/br/invoice-services.json b/examples/br/invoice-services.json
index b99630d0..dc49ef87 100644
--- a/examples/br/invoice-services.json
+++ b/examples/br/invoice-services.json
@@ -41,7 +41,7 @@
     "ext": {
       "br-nfse-municipality": "3304557",
       "br-nfse-fiscal-incentive": "1",
-      "br-nfse-simples-nacional": "1",
+      "br-nfse-simples": "1",
       "br-nfse-special-regime": "4"
     }
   },
@@ -72,13 +72,17 @@
         "name": "Consultancy Services",
         "price": "100.00",
         "ext": {
-          "br-nfse-service": "10.5"
+          "br-nfse-service": "10.5",
+          "br-nfse-cnae": "62.01-5-01"
         }
       },
       "taxes": [
         {
           "cat": "ISS",
-          "percent": "15%"
+          "percent": "15%",
+          "ext": {
+            "br-nfse-iss-liability": "1"
+          }
         }
       ]
     }
diff --git a/examples/br/out/invoice-services.json b/examples/br/out/invoice-services.json
index a8252b84..f87919ea 100644
--- a/examples/br/out/invoice-services.json
+++ b/examples/br/out/invoice-services.json
@@ -4,7 +4,7 @@
 		"uuid": "8a51fd30-2a27-11ee-be56-0242ac120002",
 		"dig": {
 			"alg": "sha256",
-			"val": "b1fc7b37b41dc9df2148365e52dd97cdc3a3847de92d5b7560b3cf40cda10f77"
+			"val": "d7ef87ccb18475563f8ce2aa804cd51e46b94c3adc6af2bb0867a72f13ad5ac1"
 		}
 	},
 	"doc": {
@@ -52,7 +52,7 @@
 			"ext": {
 				"br-nfse-fiscal-incentive": "1",
 				"br-nfse-municipality": "3304557",
-				"br-nfse-simples-nacional": "1",
+				"br-nfse-simples": "1",
 				"br-nfse-special-regime": "4"
 			}
 		},
@@ -83,6 +83,7 @@
 					"name": "Consultancy Services",
 					"price": "100.00",
 					"ext": {
+						"br-nfse-cnae": "62.01-5-01",
 						"br-nfse-service": "10.5"
 					}
 				},
@@ -90,7 +91,10 @@
 				"taxes": [
 					{
 						"cat": "ISS",
-						"percent": "15%"
+						"percent": "15%",
+						"ext": {
+							"br-nfse-iss-liability": "1"
+						}
 					}
 				],
 				"total": "1500.00"
@@ -105,6 +109,9 @@
 						"code": "ISS",
 						"rates": [
 							{
+								"ext": {
+									"br-nfse-iss-liability": "1"
+								},
 								"base": "1500.00",
 								"percent": "15%",
 								"amount": "225.00"
diff --git a/regimes/br/README.md b/regimes/br/README.md
index f9d4e34b..51272fed 100644
--- a/regimes/br/README.md
+++ b/regimes/br/README.md
@@ -25,7 +25,7 @@ For example:
 
 ```js
 "supplier": {
-  //...
+//...
   "addresses": [
     {
       "num": "75",
@@ -38,7 +38,7 @@ For example:
       "country": "BR"
     }
   ],
-  //...
+//...
 ```
 
 ### Service Notes
@@ -55,11 +55,28 @@ For example:
 
 ```js
 "supplier": {
-  //...
+//...
   "ext": {
-    "br-igbe-municipality": "2927408"
+    "br-nfse-municipality": "2927408"
   },
-  //...
+//...
+```
+
+Use the same extension at tax level when the municipality where the ISS is levied differs from the supplier's.
+
+For example:
+
+```js
+"lines": [
+  {
+//...
+    "taxes": [
+      {
+        "cat": "ISS",
+        "ext": {
+          "br-nfse-municipality": "2927408"
+        }
+//...
 ```
 
 #### National and municipal registration
@@ -70,7 +87,7 @@ For example:
 
 ```js
 "supplier": {
-  //...
+//...
   "identities": [
     {
       "key": "br-nfse-municipal-reg",
@@ -81,7 +98,7 @@ For example:
       "code": "12345012345678"
     }
   ],
-  //...
+//...
 ```
 
 #### “Simples Nacional”
@@ -97,11 +114,11 @@ For example:
 
 ```js
 "supplier": {
-  //...
+//...
   "ext": {
     "br-nfse-simples-nacional": "1", // Opt-in
   },
-  //...
+//...
 ```
 
 #### Special Tax Regime
@@ -121,11 +138,11 @@ For example:
 
 ```js
 "supplier": {
-  //...
+//...
   "ext": {
     "br-nfse-special-regime": "4" // Cooperative
   },
-  //...
+//...
 ```
 
 #### Fiscal Incentive
@@ -141,9 +158,71 @@ For example:
 
 ```js
 "supplier": {
-  //...
+//...
   "ext": {
     "br-nfse-fiscal-incentive": "2" // No tax incentive
   },
-  //...
+//...
+```
+
+#### Municipality service code
+
+Specify the code assigned by the municipality to a service using the
+`br-nfse-service` extension at item level. Typically, one of the codes listed in the [Lei Complementar 116/2003](https://www.planalto.gov.br/ccivil_03/leis/lcp/lcp116.htm), but municipalities can make their own changes.
+
+For example:
+
+```js
+"lines": [
+  {
+    "item": {
+//...
+      "ext": {
+        "br-nfse-service": "1.01"
+//...
+```
+
+#### CNAE code
+
+Set the CNAE code (National Classification of Economic Activities) for a service using the `br-nfse-cnae` at item level. Find the list of possible codes [at the IGBE](https://www.ibge.gov.br/en/statistics/technical-documents/statistical-lists-and-classifications/17245-national-classification-of-economic-activities.html).
+
+For example:
+
+```js
+"lines": [
+  {
+    "item": {
+//...
+      "ext": {
+        "br-nfse-cnae": "62.01-5-01"
+//...
+```
+
+#### ISS Liability
+
+Report the ISS liability -i.e. whether the tax is due or not and why– using the `br-nfse-iss-liability` extension at ISS tax level. Find the list of possible codes below:
+
+| Code | Description                |
+| ---- | -------------------------- |
+| `1`  | Liable (Default)           |
+| `2`  | Not subject                |
+| `3`  | Exempt                     |
+| `4`  | Export                     |
+| `5`  | Immune                     |
+| `6`  | Suspended Judicially       |
+| `7`  | Suspended Administratively |
+
+For example:
+
+```js
+"lines": [
+  {
+//...
+    "taxes": [
+      {
+        "cat": "ISS",
+        "ext": {
+          "br-nfse-iss-liability": "1"
+        }
+//...
 ```