diff --git a/CHANGELOG.md b/CHANGELOG.md
index 05a52ca4..5fba9e5b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/) and this p
 ### Fixed
 
 - `bill.Invoice` - remove empty taxes instances.
+- `tax.Identity` - support Calculate method to normalize IDs.
 
 ## [v0.202.0]
 
diff --git a/org/party.go b/org/party.go
index f9b84182..a9188aba 100644
--- a/org/party.go
+++ b/org/party.go
@@ -48,6 +48,13 @@ type Party struct {
 	Meta cbc.Meta `json:"meta,omitempty" jsonschema:"title=Meta"`
 }
 
+// Calculate will perform basic normalization of the party's data without
+// using any tax regime or addon.
+func (p *Party) Calculate() error {
+	p.Normalize(nil)
+	return nil
+}
+
 // Normalize will try to normalize the party's data.
 func (p *Party) Normalize(normalizers tax.Normalizers) {
 	if p == nil {
diff --git a/org/party_test.go b/org/party_test.go
index 5ed3fd7a..bd1ced11 100644
--- a/org/party_test.go
+++ b/org/party_test.go
@@ -22,27 +22,44 @@ func TestEmailValidation(t *testing.T) {
 	assert.EqualError(t, invalid.Validate(), "addr: must be a valid email address.")
 }
 
-func TestPartyCalculate(t *testing.T) {
-	party := org.Party{
-		Name: "Invopop",
-		TaxID: &tax.Identity{
-			Country: "ES",
-			Code:    "423 429 12.G",
-		},
-	}
-	party.Normalize(nil)
-	assert.Equal(t, "ES", party.TaxID.Country.String())
-	assert.Equal(t, "ES42342912G", party.TaxID.String())
-
-	party = org.Party{
-		Name: "Invopop",
-		TaxID: &tax.Identity{
-			Country: "ZZ", // no country has ZZ!
-			Code:    "423 429 12.G",
-		},
-	}
-	party.Normalize(nil) // unknown entry should not cause problem
-	assert.Equal(t, "42342912G", party.TaxID.Code.String())
+func TestPartyNormalize(t *testing.T) {
+	t.Run("for known regime", func(t *testing.T) {
+		party := org.Party{
+			Name: "Invopop",
+			TaxID: &tax.Identity{
+				Country: "ES",
+				Code:    "423 429 12.G",
+			},
+		}
+		party.Normalize(nil)
+		assert.Equal(t, "ES", party.TaxID.Country.String())
+		assert.Equal(t, "ES42342912G", party.TaxID.String())
+	})
+
+	t.Run("for known regime with Calculate", func(t *testing.T) {
+		party := org.Party{
+			Name: "Invopop",
+			TaxID: &tax.Identity{
+				Country: "ES",
+				Code:    "423 429 12.G",
+			},
+		}
+		assert.NoError(t, party.Calculate())
+		assert.Equal(t, "ES", party.TaxID.Country.String())
+		assert.Equal(t, "ES42342912G", party.TaxID.String())
+	})
+
+	t.Run("for unknown regime", func(t *testing.T) {
+		party := org.Party{
+			Name: "Invopop",
+			TaxID: &tax.Identity{
+				Country: "ZZ", // no country has ZZ!
+				Code:    "423 429 12.G",
+			},
+		}
+		party.Normalize(nil) // unknown entry should not cause problem
+		assert.Equal(t, "42342912G", party.TaxID.Code.String())
+	})
 }
 
 func TestPartyAddressNill(t *testing.T) {
diff --git a/regimes/es/examples/out/party.json b/regimes/es/examples/out/party.json
new file mode 100644
index 00000000..f92f650e
--- /dev/null
+++ b/regimes/es/examples/out/party.json
@@ -0,0 +1,34 @@
+{
+	"$schema": "https://gobl.org/draft-0/envelope",
+	"head": {
+		"uuid": "8a51fd30-2a27-11ee-be56-0242ac120002",
+		"dig": {
+			"alg": "sha256",
+			"val": "eb13b8883977bbd80419ce394072232e235c13c9325a4dda3693da85d86f3396"
+		}
+	},
+	"doc": {
+		"$schema": "https://gobl.org/draft-0/org/party",
+		"uuid": "0192a13b-7f85-7429-a635-b269f6eb5295",
+		"name": "Provide One S.L.",
+		"tax_id": {
+			"country": "ES",
+			"code": "B98602642"
+		},
+		"addresses": [
+			{
+				"num": "42",
+				"street": "Calle Pradillo",
+				"locality": "Madrid",
+				"region": "Madrid",
+				"code": "28002",
+				"country": "ES"
+			}
+		],
+		"emails": [
+			{
+				"addr": "billing@example.com"
+			}
+		]
+	}
+}
\ No newline at end of file
diff --git a/regimes/es/examples/out/tax-identity.json b/regimes/es/examples/out/tax-identity.json
new file mode 100644
index 00000000..273d1864
--- /dev/null
+++ b/regimes/es/examples/out/tax-identity.json
@@ -0,0 +1,15 @@
+{
+	"$schema": "https://gobl.org/draft-0/envelope",
+	"head": {
+		"uuid": "8a51fd30-2a27-11ee-be56-0242ac120002",
+		"dig": {
+			"alg": "sha256",
+			"val": "3630785426ac28dd900af9bd1ea51cf5ed783896dfe954773ad1d88058267453"
+		}
+	},
+	"doc": {
+		"$schema": "https://gobl.org/draft-0/tax/identity",
+		"country": "ES",
+		"code": "B98602642"
+	}
+}
\ No newline at end of file
diff --git a/regimes/es/examples/party.yaml b/regimes/es/examples/party.yaml
new file mode 100644
index 00000000..e78730f6
--- /dev/null
+++ b/regimes/es/examples/party.yaml
@@ -0,0 +1,15 @@
+$schema: "https://gobl.org/draft-0/org/party"
+uuid: "0192a13b-7f85-7429-a635-b269f6eb5295"
+tax_id:
+  country: "ES"
+  code: "B-986.026.42" # test normalization
+name: "Provide One S.L."
+emails:
+  - addr: "billing@example.com"
+addresses:
+  - num: "42"
+    street: "Calle Pradillo"
+    locality: "Madrid"
+    region: "Madrid"
+    code: "28002"
+    country: "ES"
diff --git a/regimes/es/examples/tax-identity.yaml b/regimes/es/examples/tax-identity.yaml
new file mode 100644
index 00000000..431dbf98
--- /dev/null
+++ b/regimes/es/examples/tax-identity.yaml
@@ -0,0 +1,3 @@
+$schema: "https://gobl.org/draft-0/tax/identity"
+country: "ES"
+code: "B-986.026.42" # test normalization
diff --git a/tax/identity.go b/tax/identity.go
index 7fd51b9a..ddcba831 100644
--- a/tax/identity.go
+++ b/tax/identity.go
@@ -98,6 +98,12 @@ func (id *Identity) Regime() *RegimeDef {
 	return regimes.For(id.Country.Code())
 }
 
+// Calculate will simply perform normalization.
+func (id *Identity) Calculate() error {
+	id.Normalize()
+	return nil
+}
+
 // Normalize will attempt to perform a regional tax normalization
 // on the tax identity. Identities are an exception to the normal
 // normalization rules as they cannot be normalized using addons.
diff --git a/tax/identity_test.go b/tax/identity_test.go
index a18bcaa6..e3cef616 100644
--- a/tax/identity_test.go
+++ b/tax/identity_test.go
@@ -102,4 +102,13 @@ func TestIdentityNormalize(t *testing.T) {
 		tID.Normalize()
 		assert.Equal(t, tID.Code.String(), "39356000000") // adds 2 0s on end
 	})
+	t.Run("with calculate method", func(t *testing.T) {
+		tID := &tax.Identity{
+			Country: "FR",
+			Code:    " 356000000 ",
+		}
+		err := tID.Calculate()
+		assert.NoError(t, err)
+		assert.Equal(t, tID.Code.String(), "39356000000")
+	})
 }