diff --git a/pkg/api/pluginproxy/ds_proxy_test.go b/pkg/api/pluginproxy/ds_proxy_test.go
index eeb533bf4a1..59776394ab4 100644
--- a/pkg/api/pluginproxy/ds_proxy_test.go
+++ b/pkg/api/pluginproxy/ds_proxy_test.go
@@ -30,6 +30,7 @@ import (
 	"github.com/grafana/grafana/pkg/services/accesscontrol/acimpl"
 	"github.com/grafana/grafana/pkg/services/accesscontrol/actest"
 	"github.com/grafana/grafana/pkg/services/auth/identity"
+	"github.com/grafana/grafana/pkg/services/authn"
 	contextmodel "github.com/grafana/grafana/pkg/services/contexthandler/model"
 	"github.com/grafana/grafana/pkg/services/datasources"
 	datasourceservice "github.com/grafana/grafana/pkg/services/datasources/service"
@@ -514,7 +515,7 @@ func TestDataSourceProxy_routeRule(t *testing.T) {
 			&contextmodel.ReqContext{
 				SignedInUser: &user.SignedInUser{
 					Login:        "test_user",
-					NamespacedID: "user:1",
+					NamespacedID: authn.MustParseNamespaceID("user:1"),
 				},
 			},
 			&setting.Cfg{SendUserHeader: true},
diff --git a/pkg/api/pluginproxy/pluginproxy_test.go b/pkg/api/pluginproxy/pluginproxy_test.go
index 8b6185510ef..556f0a7265f 100644
--- a/pkg/api/pluginproxy/pluginproxy_test.go
+++ b/pkg/api/pluginproxy/pluginproxy_test.go
@@ -15,6 +15,7 @@ import (
 	"github.com/grafana/grafana/pkg/infra/tracing"
 	"github.com/grafana/grafana/pkg/plugins"
 	"github.com/grafana/grafana/pkg/services/accesscontrol/acimpl"
+	"github.com/grafana/grafana/pkg/services/authn"
 	contextmodel "github.com/grafana/grafana/pkg/services/contexthandler/model"
 	"github.com/grafana/grafana/pkg/services/featuremgmt"
 	"github.com/grafana/grafana/pkg/services/org"
@@ -77,7 +78,7 @@ func TestPluginProxy(t *testing.T) {
 			&contextmodel.ReqContext{
 				SignedInUser: &user.SignedInUser{
 					Login:        "test_user",
-					NamespacedID: "user:1",
+					NamespacedID: authn.MustParseNamespaceID("user:1"),
 				},
 				Context: &web.Context{
 					Req: httpReq,
diff --git a/pkg/services/accesscontrol/acimpl/service_test.go b/pkg/services/accesscontrol/acimpl/service_test.go
index c222de708ca..8ce30216268 100644
--- a/pkg/services/accesscontrol/acimpl/service_test.go
+++ b/pkg/services/accesscontrol/acimpl/service_test.go
@@ -756,7 +756,7 @@ func TestPermissionCacheKey(t *testing.T) {
 			signedInUser: &user.SignedInUser{
 				OrgID:        1,
 				UserID:       1,
-				NamespacedID: "user:1",
+				NamespacedID: identity.MustParseNamespaceID("user:1"),
 			},
 			expected: "rbac-permissions-1-user-1",
 		},
@@ -766,7 +766,7 @@ func TestPermissionCacheKey(t *testing.T) {
 				OrgID:            1,
 				ApiKeyID:         1,
 				IsServiceAccount: false,
-				NamespacedID:     "user:1",
+				NamespacedID:     identity.MustParseNamespaceID("user:1"),
 			},
 			expected: "rbac-permissions-1-api-key-1",
 		},
@@ -776,7 +776,7 @@ func TestPermissionCacheKey(t *testing.T) {
 				OrgID:            1,
 				UserID:           1,
 				IsServiceAccount: true,
-				NamespacedID:     "serviceaccount:1",
+				NamespacedID:     identity.MustParseNamespaceID("service-account:1"),
 			},
 			expected: "rbac-permissions-1-service-account-1",
 		},
@@ -786,7 +786,7 @@ func TestPermissionCacheKey(t *testing.T) {
 				OrgID:            1,
 				UserID:           -1,
 				IsServiceAccount: true,
-				NamespacedID:     "serviceaccount:-1",
+				NamespacedID:     identity.MustParseNamespaceID("service-account:-1"),
 			},
 			expected: "rbac-permissions-1-service-account--1",
 		},
@@ -795,7 +795,7 @@ func TestPermissionCacheKey(t *testing.T) {
 			signedInUser: &user.SignedInUser{
 				OrgID:        1,
 				OrgRole:      org.RoleNone,
-				NamespacedID: "user:1",
+				NamespacedID: identity.MustParseNamespaceID("user:1"),
 			},
 			expected: "rbac-permissions-1-user-None",
 		},
diff --git a/pkg/services/auth/identity/requester.go b/pkg/services/auth/identity/requester.go
index 87140b85d4f..3be473ec0a3 100644
--- a/pkg/services/auth/identity/requester.go
+++ b/pkg/services/auth/identity/requester.go
@@ -9,7 +9,7 @@ import (
 
 type Requester interface {
 	// GetID returns namespaced id for the entity
-	GetID() string
+	GetID() NamespaceID
 	// GetNamespacedID returns the namespace and ID of the active entity.
 	// The namespace is one of the constants defined in pkg/services/auth/identity.
 	GetNamespacedID() (namespace string, identifier string)
diff --git a/pkg/services/authn/authn.go b/pkg/services/authn/authn.go
index 83cbc622bf9..69e7faaaa55 100644
--- a/pkg/services/authn/authn.go
+++ b/pkg/services/authn/authn.go
@@ -90,7 +90,7 @@ type Service interface {
 	Logout(ctx context.Context, user identity.Requester, sessionToken *usertoken.UserToken) (*Redirect, error)
 
 	// ResolveIdentity resolves an identity from org and namespace id.
-	ResolveIdentity(ctx context.Context, orgID int64, namespaceID string) (*Identity, error)
+	ResolveIdentity(ctx context.Context, orgID int64, namespaceID NamespaceID) (*Identity, error)
 
 	// RegisterClient will register a new authn.Client that can be used for authentication
 	RegisterClient(c Client)
diff --git a/pkg/services/authn/authnimpl/service.go b/pkg/services/authn/authnimpl/service.go
index 2b12e1021f6..425236a5ef6 100644
--- a/pkg/services/authn/authnimpl/service.go
+++ b/pkg/services/authn/authnimpl/service.go
@@ -308,18 +308,13 @@ Default:
 	return redirect, nil
 }
 
-func (s *Service) ResolveIdentity(ctx context.Context, orgID int64, namespaceID string) (*authn.Identity, error) {
+func (s *Service) ResolveIdentity(ctx context.Context, orgID int64, namespaceID authn.NamespaceID) (*authn.Identity, error) {
 	r := &authn.Request{}
 	r.OrgID = orgID
 	// hack to not update last seen
 	r.SetMeta(authn.MetaKeyIsLogin, "true")
 
-	id, err := authn.ParseNamespaceID(namespaceID)
-	if err != nil {
-		return nil, err
-	}
-
-	identity, err := s.resolveIdenity(ctx, orgID, id)
+	identity, err := s.resolveIdenity(ctx, orgID, namespaceID)
 	if err != nil {
 		return nil, err
 	}
diff --git a/pkg/services/authn/authnimpl/service_test.go b/pkg/services/authn/authnimpl/service_test.go
index dd2592f89d7..9795d136343 100644
--- a/pkg/services/authn/authnimpl/service_test.go
+++ b/pkg/services/authn/authnimpl/service_test.go
@@ -487,26 +487,26 @@ func TestService_Logout(t *testing.T) {
 func TestService_ResolveIdentity(t *testing.T) {
 	t.Run("should return error for for unknown namespace", func(t *testing.T) {
 		svc := setupTests(t)
-		_, err := svc.ResolveIdentity(context.Background(), 1, "some:1")
-		assert.ErrorIs(t, err, authn.ErrInvalidNamespaceID)
+		_, err := svc.ResolveIdentity(context.Background(), 1, authn.NewNamespaceIDUnchecked("some", 1))
+		assert.ErrorIs(t, err, authn.ErrUnsupportedIdentity)
 	})
 
 	t.Run("should return error for for namespace that don't have a resolver", func(t *testing.T) {
 		svc := setupTests(t)
-		_, err := svc.ResolveIdentity(context.Background(), 1, "api-key:1")
+		_, err := svc.ResolveIdentity(context.Background(), 1, authn.MustParseNamespaceID("api-key:1"))
 		assert.ErrorIs(t, err, authn.ErrUnsupportedIdentity)
 	})
 
 	t.Run("should resolve for user", func(t *testing.T) {
 		svc := setupTests(t)
-		identity, err := svc.ResolveIdentity(context.Background(), 1, "user:1")
+		identity, err := svc.ResolveIdentity(context.Background(), 1, authn.MustParseNamespaceID("user:1"))
 		assert.NoError(t, err)
 		assert.NotNil(t, identity)
 	})
 
 	t.Run("should resolve for service account", func(t *testing.T) {
 		svc := setupTests(t)
-		identity, err := svc.ResolveIdentity(context.Background(), 1, "service-account:1")
+		identity, err := svc.ResolveIdentity(context.Background(), 1, authn.MustParseNamespaceID("service-account:1"))
 		assert.NoError(t, err)
 		assert.NotNil(t, identity)
 	})
@@ -521,7 +521,7 @@ func TestService_ResolveIdentity(t *testing.T) {
 			})
 		})
 
-		identity, err := svc.ResolveIdentity(context.Background(), 1, "api-key:1")
+		identity, err := svc.ResolveIdentity(context.Background(), 1, authn.MustParseNamespaceID("api-key:1"))
 		assert.NoError(t, err)
 		assert.NotNil(t, identity)
 	})
diff --git a/pkg/services/authn/authntest/fake.go b/pkg/services/authn/authntest/fake.go
index c65b2d7f7fb..f88e3384291 100644
--- a/pkg/services/authn/authntest/fake.go
+++ b/pkg/services/authn/authntest/fake.go
@@ -76,7 +76,7 @@ func (f *FakeService) Logout(_ context.Context, _ identity.Requester, _ *usertok
 	panic("unimplemented")
 }
 
-func (f *FakeService) ResolveIdentity(ctx context.Context, orgID int64, namespaceID string) (*authn.Identity, error) {
+func (f *FakeService) ResolveIdentity(ctx context.Context, orgID int64, namespaceID authn.NamespaceID) (*authn.Identity, error) {
 	if f.ExpectedIdentities != nil {
 		if f.CurrentIndex >= len(f.ExpectedIdentities) {
 			panic("ExpectedIdentities is empty")
diff --git a/pkg/services/authn/authntest/mock.go b/pkg/services/authn/authntest/mock.go
index f2d7d77d9b1..63dc12a8745 100644
--- a/pkg/services/authn/authntest/mock.go
+++ b/pkg/services/authn/authntest/mock.go
@@ -50,7 +50,7 @@ func (*MockService) Logout(_ context.Context, _ identity.Requester, _ *usertoken
 	panic("unimplemented")
 }
 
-func (m *MockService) ResolveIdentity(ctx context.Context, orgID int64, namespaceID string) (*authn.Identity, error) {
+func (m *MockService) ResolveIdentity(ctx context.Context, orgID int64, namespaceID authn.NamespaceID) (*authn.Identity, error) {
 	panic("unimplemented")
 }
 
diff --git a/pkg/services/authn/identity.go b/pkg/services/authn/identity.go
index 38d9a51c67b..51fc542fae9 100644
--- a/pkg/services/authn/identity.go
+++ b/pkg/services/authn/identity.go
@@ -73,8 +73,8 @@ type Identity struct {
 	IDToken string
 }
 
-func (i *Identity) GetID() string {
-	return i.ID.String()
+func (i *Identity) GetID() NamespaceID {
+	return i.ID
 }
 
 func (i *Identity) GetNamespacedID() (namespace string, identifier string) {
@@ -220,7 +220,7 @@ func (i *Identity) SignedInUser() *user.SignedInUser {
 		Teams:           i.Teams,
 		Permissions:     i.Permissions,
 		IDToken:         i.IDToken,
-		NamespacedID:    i.ID.String(),
+		NamespacedID:    i.ID,
 	}
 
 	if namespace == NamespaceAPIKey {
diff --git a/pkg/services/user/identity.go b/pkg/services/user/identity.go
index 3d9d2fab649..5cd3ffe2622 100644
--- a/pkg/services/user/identity.go
+++ b/pkg/services/user/identity.go
@@ -2,7 +2,6 @@ package user
 
 import (
 	"fmt"
-	"strings"
 	"time"
 
 	"github.com/grafana/grafana/pkg/models/roletype"
@@ -40,7 +39,7 @@ type SignedInUser struct {
 	// IDToken is a signed token representing the identity that can be forwarded to plugins and external services.
 	// Will only be set when featuremgmt.FlagIdForwarding is enabled.
 	IDToken      string `json:"-" xorm:"-"`
-	NamespacedID string
+	NamespacedID identity.NamespaceID
 }
 
 func (u *SignedInUser) ShouldUpdateLastSeenAt() bool {
@@ -196,7 +195,7 @@ func (u *SignedInUser) GetOrgRole() roletype.RoleType {
 }
 
 // GetID returns namespaced id for the entity
-func (u *SignedInUser) GetID() string {
+func (u *SignedInUser) GetID() identity.NamespaceID {
 	switch {
 	case u.ApiKeyID != 0:
 		return namespacedID(identity.NamespaceAPIKey, u.ApiKeyID)
@@ -205,7 +204,7 @@ func (u *SignedInUser) GetID() string {
 	case u.UserID > 0:
 		return namespacedID(identity.NamespaceUser, u.UserID)
 	case u.IsAnonymous:
-		return identity.NamespaceAnonymous + ":"
+		return namespacedID(identity.NamespaceAnonymous, 0)
 	case u.AuthenticatedBy == "render" && u.UserID == 0:
 		return namespacedID(identity.NamespaceRenderService, 0)
 	}
@@ -216,13 +215,8 @@ func (u *SignedInUser) GetID() string {
 // GetNamespacedID returns the namespace and ID of the active entity
 // The namespace is one of the constants defined in pkg/services/auth/identity
 func (u *SignedInUser) GetNamespacedID() (string, string) {
-	parts := strings.Split(u.GetID(), ":")
-	// Safety: GetID always returns a ':' separated string
-	if len(parts) != 2 {
-		return "", ""
-	}
-
-	return parts[0], parts[1]
+	id := u.GetID()
+	return id.Namespace(), id.ID()
 }
 
 func (u *SignedInUser) GetAuthID() string {
@@ -267,6 +261,6 @@ func (u *SignedInUser) GetIDToken() string {
 	return u.IDToken
 }
 
-func namespacedID(namespace string, id int64) string {
-	return fmt.Sprintf("%s:%d", namespace, id)
+func namespacedID(namespace string, id int64) identity.NamespaceID {
+	return identity.NewNamespaceIDUnchecked(namespace, id)
 }
diff --git a/pkg/util/proxyutil/proxyutil_test.go b/pkg/util/proxyutil/proxyutil_test.go
index 10eb6c536e7..d84578f638a 100644
--- a/pkg/util/proxyutil/proxyutil_test.go
+++ b/pkg/util/proxyutil/proxyutil_test.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/stretchr/testify/require"
 
+	"github.com/grafana/grafana/pkg/services/auth/identity"
 	"github.com/grafana/grafana/pkg/services/user"
 )
 
@@ -174,7 +175,7 @@ func TestApplyUserHeader(t *testing.T) {
 		require.NoError(t, err)
 		req.Header.Set("X-Grafana-User", "admin")
 
-		ApplyUserHeader(false, req, &user.SignedInUser{Login: "admin", NamespacedID: "user:1"})
+		ApplyUserHeader(false, req, &user.SignedInUser{Login: "admin", NamespacedID: identity.MustParseNamespaceID("user:1")})
 		require.NotContains(t, req.Header, "X-Grafana-User")
 	})
 
@@ -191,7 +192,7 @@ func TestApplyUserHeader(t *testing.T) {
 		req, err := http.NewRequest(http.MethodGet, "/", nil)
 		require.NoError(t, err)
 
-		ApplyUserHeader(true, req, &user.SignedInUser{IsAnonymous: true, NamespacedID: "anonymous:1"})
+		ApplyUserHeader(true, req, &user.SignedInUser{IsAnonymous: true, NamespacedID: identity.MustParseNamespaceID("anonymous:0")})
 		require.NotContains(t, req.Header, "X-Grafana-User")
 	})
 
@@ -199,7 +200,7 @@ func TestApplyUserHeader(t *testing.T) {
 		req, err := http.NewRequest(http.MethodGet, "/", nil)
 		require.NoError(t, err)
 
-		ApplyUserHeader(true, req, &user.SignedInUser{Login: "admin", NamespacedID: "user:1"})
+		ApplyUserHeader(true, req, &user.SignedInUser{Login: "admin", NamespacedID: identity.MustParseNamespaceID("user:1")})
 		require.Equal(t, "admin", req.Header.Get("X-Grafana-User"))
 	})
 }