diff --git a/auth/auth.go b/auth/auth.go
index 0bda04a0..a7028698 100644
--- a/auth/auth.go
+++ b/auth/auth.go
@@ -21,7 +21,6 @@ import (
 	"errors"
 	"fmt"
 	"os"
-	"runtime"
 	"strings"
 	"time"
 
@@ -134,12 +133,11 @@ func NewClient(ctx context.Context, conf *internal.AuthConfig) (*Client, error)
 		return nil, err
 	}
 
-	goVersion := strings.TrimPrefix(runtime.Version(), "go")
 	hc := internal.WithDefaultRetryConfig(transport)
 	hc.CreateErrFn = handleHTTPError
 	hc.Opts = []internal.HTTPOption{
 		internal.WithHeader("X-Client-Version", fmt.Sprintf("Go/Admin/%s", conf.Version)),
-		internal.WithHeader("x-goog-api-client", fmt.Sprintf("gl-go/%s fire-admin/%s", goVersion, conf.Version)),
+		internal.WithHeader("x-goog-api-client", internal.GetMetricsHeader(conf.Version)),
 	}
 
 	baseURL := defaultAuthURL
diff --git a/auth/auth_test.go b/auth/auth_test.go
index 2a00220b..9c8b1523 100644
--- a/auth/auth_test.go
+++ b/auth/auth_test.go
@@ -23,7 +23,6 @@ import (
 	"log"
 	"net/http"
 	"os"
-	"runtime"
 	"strings"
 	"syscall"
 	"testing"
@@ -1452,11 +1451,9 @@ func checkBaseClient(client *Client, wantProjectID string) error {
 		return fmt.Errorf("version = %q; want = %q", version, wantVersion)
 	}
 
-	goVersion := strings.TrimPrefix(runtime.Version(), "go")
-	xGoogAPIClientHeader := req.Header.Get("x-goog-api-client")
-	wantXGoogAPIClientHeader := fmt.Sprintf("gl-go/%s fire-admin/%s", goVersion, testVersion)
-	if xGoogAPIClientHeader != wantXGoogAPIClientHeader {
-		return fmt.Errorf("x-goog-api-client header = %q; want = %q", xGoogAPIClientHeader, wantXGoogAPIClientHeader)
+	xGoogAPIClientHeader := internal.GetMetricsHeader(testVersion)
+	if h := req.Header.Get("x-goog-api-client"); h != xGoogAPIClientHeader {
+		return fmt.Errorf("x-goog-api-client header = %q; want = %q", h, xGoogAPIClientHeader)
 	}
 
 	return nil
diff --git a/auth/token_generator.go b/auth/token_generator.go
index 0e18b8c8..7aa2d564 100644
--- a/auth/token_generator.go
+++ b/auth/token_generator.go
@@ -175,6 +175,9 @@ func newIAMSigner(ctx context.Context, config *internal.AuthConfig) (*iamSigner,
 	if err != nil {
 		return nil, err
 	}
+	hc.Opts = []internal.HTTPOption{
+		internal.WithHeader("x-goog-api-client", internal.GetMetricsHeader(config.Version)),
+	}
 
 	return &iamSigner{
 		mutex:        &sync.Mutex{},
diff --git a/auth/token_generator_test.go b/auth/token_generator_test.go
index c80c4dea..c79e3a9a 100644
--- a/auth/token_generator_test.go
+++ b/auth/token_generator_test.go
@@ -122,6 +122,7 @@ func TestIAMSigner(t *testing.T) {
 	conf := &internal.AuthConfig{
 		Opts:             optsWithTokenSource,
 		ServiceAccountID: "test-service-account",
+		Version:          testVersion,
 	}
 	signer, err := newIAMSigner(ctx, conf)
 	if err != nil {
@@ -155,6 +156,7 @@ func TestIAMSignerHTTPError(t *testing.T) {
 	conf := &internal.AuthConfig{
 		Opts:             optsWithTokenSource,
 		ServiceAccountID: "test-service-account",
+		Version:          testVersion,
 	}
 	signer, err := newIAMSigner(context.Background(), conf)
 	if err != nil {
@@ -182,6 +184,7 @@ func TestIAMSignerUnknownHTTPError(t *testing.T) {
 	conf := &internal.AuthConfig{
 		Opts:             optsWithTokenSource,
 		ServiceAccountID: "test-service-account",
+		Version:          testVersion,
 	}
 	signer, err := newIAMSigner(context.Background(), conf)
 	if err != nil {
@@ -208,7 +211,8 @@ func TestIAMSignerUnknownHTTPError(t *testing.T) {
 func TestIAMSignerWithMetadataService(t *testing.T) {
 	ctx := context.Background()
 	conf := &internal.AuthConfig{
-		Opts: optsWithTokenSource,
+		Opts:    optsWithTokenSource,
+		Version: testVersion,
 	}
 
 	signer, err := newIAMSigner(ctx, conf)
@@ -253,7 +257,8 @@ func TestIAMSignerWithMetadataService(t *testing.T) {
 func TestIAMSignerNoMetadataService(t *testing.T) {
 	ctx := context.Background()
 	conf := &internal.AuthConfig{
-		Opts: optsWithTokenSource,
+		Opts:    optsWithTokenSource,
+		Version: testVersion,
 	}
 
 	signer, err := newIAMSigner(ctx, conf)
@@ -340,6 +345,10 @@ func iamServer(t *testing.T, serviceAcct, signature string) *httptest.Server {
 		if r.URL.Path != wantPath {
 			t.Errorf("Path = %q; want = %q", r.URL.Path, wantPath)
 		}
+		xGoogAPIClientHeader := internal.GetMetricsHeader(testVersion)
+		if h := r.Header.Get("x-goog-api-client"); h != xGoogAPIClientHeader {
+			t.Errorf("x-goog-api-client header = %q; want = %q", h, xGoogAPIClientHeader)
+		}
 
 		w.Header().Set("Content-Type", "application/json")
 		b, err := json.Marshal(resp)
diff --git a/auth/user_mgt_test.go b/auth/user_mgt_test.go
index 902ed280..97e64c39 100644
--- a/auth/user_mgt_test.go
+++ b/auth/user_mgt_test.go
@@ -24,7 +24,6 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"reflect"
-	"runtime"
 	"sort"
 	"strconv"
 	"strings"
@@ -2317,7 +2316,7 @@ func echoServer(resp interface{}, t *testing.T) *mockAuthServer {
 		}
 
 		gh = r.Header.Get("x-goog-api-client")
-		wh = fmt.Sprintf("gl-go/%s fire-admin/%s", strings.TrimPrefix(runtime.Version(), "go"), testVersion)
+		wh = internal.GetMetricsHeader(testVersion)
 		if gh != wh {
 			t.Errorf("x-goog-api-client header = %q; want: %q", gh, wh)
 		}
diff --git a/firebase.go b/firebase.go
index 8b1facd4..98e04a07 100644
--- a/firebase.go
+++ b/firebase.go
@@ -115,6 +115,7 @@ func (a *App) InstanceID(ctx context.Context) (*iid.Client, error) {
 	conf := &internal.InstanceIDConfig{
 		ProjectID: a.projectID,
 		Opts:      a.opts,
+		Version:   Version,
 	}
 	return iid.NewClient(ctx, conf)
 }
diff --git a/iid/iid.go b/iid/iid.go
index 96486a6a..7a3e9b55 100644
--- a/iid/iid.go
+++ b/iid/iid.go
@@ -119,6 +119,9 @@ func NewClient(ctx context.Context, c *internal.InstanceIDConfig) (*Client, erro
 	if err != nil {
 		return nil, err
 	}
+	hc.Opts = []internal.HTTPOption{
+		internal.WithHeader("x-goog-api-client", internal.GetMetricsHeader(c.Version)),
+	}
 
 	hc.CreateErrFn = createError
 	return &Client{
diff --git a/iid/iid_test.go b/iid/iid_test.go
index c9134207..208da357 100644
--- a/iid/iid_test.go
+++ b/iid/iid_test.go
@@ -31,6 +31,7 @@ var testIIDConfig = &internal.InstanceIDConfig{
 	Opts: []option.ClientOption{
 		option.WithTokenSource(&internal.MockTokenSource{AccessToken: "test-token"}),
 	},
+	Version: "test-version",
 }
 
 func TestNoProjectID(t *testing.T) {
@@ -83,6 +84,10 @@ func TestDeleteInstanceID(t *testing.T) {
 	if h := tr.Header.Get("Authorization"); h != "Bearer test-token" {
 		t.Errorf("Authorization = %q; want = %q", h, "Bearer test-token")
 	}
+	xGoogAPIClientHeader := internal.GetMetricsHeader(testIIDConfig.Version)
+	if h := tr.Header.Get("x-goog-api-client"); h != xGoogAPIClientHeader {
+		t.Errorf("x-goog-api-client header = %q; want = %q", h, xGoogAPIClientHeader)
+	}
 }
 
 func TestDeleteInstanceIDError(t *testing.T) {
@@ -156,6 +161,10 @@ func TestDeleteInstanceIDError(t *testing.T) {
 		if h := tr.Header.Get("Authorization"); h != "Bearer test-token" {
 			t.Errorf("Authorization = %q; want = %q", h, "Bearer test-token")
 		}
+		xGoogAPIClientHeader := internal.GetMetricsHeader(testIIDConfig.Version)
+		if h := tr.Header.Get("x-goog-api-client"); h != xGoogAPIClientHeader {
+			t.Errorf("x-goog-api-client header = %q; want = %q", h, xGoogAPIClientHeader)
+		}
 		tr = nil
 	}
 }
@@ -201,6 +210,10 @@ func TestDeleteInstanceIDUnexpectedError(t *testing.T) {
 	if h := tr.Header.Get("Authorization"); h != "Bearer test-token" {
 		t.Errorf("Authorization = %q; want = %q", h, "Bearer test-token")
 	}
+	xGoogAPIClientHeader := internal.GetMetricsHeader(testIIDConfig.Version)
+	if h := tr.Header.Get("x-goog-api-client"); h != xGoogAPIClientHeader {
+		t.Errorf("x-goog-api-client header = %q; want = %q", h, xGoogAPIClientHeader)
+	}
 }
 
 func TestDeleteInstanceIDConnectionError(t *testing.T) {
diff --git a/internal/http_client.go b/internal/http_client.go
index 280aecc4..9463f98e 100644
--- a/internal/http_client.go
+++ b/internal/http_client.go
@@ -23,7 +23,9 @@ import (
 	"io/ioutil"
 	"math"
 	"net/http"
+	"runtime"
 	"strconv"
+	"strings"
 	"time"
 
 	"google.golang.org/api/option"
@@ -441,3 +443,9 @@ func retryNetworkAndHTTPErrors(statusCodes ...int) RetryCondition {
 		return false
 	}
 }
+
+// GetMetricsHeader constructs header value for metrics attribution
+func GetMetricsHeader(sdkVersion string) string {
+	goVersion := strings.TrimPrefix(runtime.Version(), "go")
+	return fmt.Sprintf("gl-go/%s fire-admin/%s", goVersion, sdkVersion)
+}
diff --git a/internal/internal.go b/internal/internal.go
index 287391c5..9fb9e726 100644
--- a/internal/internal.go
+++ b/internal/internal.go
@@ -50,6 +50,7 @@ type HashConfig map[string]interface{}
 type InstanceIDConfig struct {
 	Opts      []option.ClientOption
 	ProjectID string
+	Version   string
 }
 
 // DatabaseConfig represents the configuration of Firebase Database service.
diff --git a/messaging/messaging.go b/messaging/messaging.go
index 525cccb6..dcd412c3 100644
--- a/messaging/messaging.go
+++ b/messaging/messaging.go
@@ -23,7 +23,6 @@ import (
 	"fmt"
 	"net/http"
 	"regexp"
-	"runtime"
 	"strconv"
 	"strings"
 	"time"
@@ -878,7 +877,7 @@ func NewClient(ctx context.Context, c *internal.MessagingConfig) (*Client, error
 
 	return &Client{
 		fcmClient: newFCMClient(hc, c, messagingEndpoint, batchEndpoint),
-		iidClient: newIIDClient(hc),
+		iidClient: newIIDClient(hc, c),
 	}, nil
 }
 
@@ -894,12 +893,11 @@ func newFCMClient(hc *http.Client, conf *internal.MessagingConfig, messagingEndp
 	client := internal.WithDefaultRetryConfig(hc)
 	client.CreateErrFn = handleFCMError
 
-	goVersion := strings.TrimPrefix(runtime.Version(), "go")
 	version := fmt.Sprintf("fire-admin-go/%s", conf.Version)
 	client.Opts = []internal.HTTPOption{
 		internal.WithHeader(apiFormatVersionHeader, apiFormatVersion),
 		internal.WithHeader(firebaseClientHeader, version),
-		internal.WithHeader("x-goog-api-client", fmt.Sprintf("gl-go/%s fire-admin/%s", goVersion, conf.Version)),
+		internal.WithHeader("x-goog-api-client", internal.GetMetricsHeader(conf.Version)),
 	}
 
 	return &fcmClient{
diff --git a/messaging/messaging_test.go b/messaging/messaging_test.go
index 8b31fc46..dceed542 100644
--- a/messaging/messaging_test.go
+++ b/messaging/messaging_test.go
@@ -21,8 +21,6 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"reflect"
-	"runtime"
-	"strings"
 	"testing"
 	"time"
 
@@ -1396,8 +1394,7 @@ func checkFCMRequest(t *testing.T, b []byte, tr *http.Request, want map[string]i
 	if h := tr.Header.Get("X-FIREBASE-CLIENT"); h != clientVersion {
 		t.Errorf("X-FIREBASE-CLIENT = %q; want = %q", h, clientVersion)
 	}
-	goVersion := strings.TrimPrefix(runtime.Version(), "go")
-	xGoogAPIClientHeader := "gl-go/" + goVersion + " fire-admin/" + testMessagingConfig.Version
+	xGoogAPIClientHeader := internal.GetMetricsHeader(testMessagingConfig.Version)
 	if h := tr.Header.Get("x-goog-api-client"); h != xGoogAPIClientHeader {
 		t.Errorf("x-goog-api-client header = %q; want = %q", h, xGoogAPIClientHeader)
 	}
diff --git a/messaging/topic_mgt.go b/messaging/topic_mgt.go
index 15a29787..88492585 100644
--- a/messaging/topic_mgt.go
+++ b/messaging/topic_mgt.go
@@ -63,10 +63,13 @@ type iidClient struct {
 	httpClient  *internal.HTTPClient
 }
 
-func newIIDClient(hc *http.Client) *iidClient {
+func newIIDClient(hc *http.Client, conf *internal.MessagingConfig) *iidClient {
 	client := internal.WithDefaultRetryConfig(hc)
 	client.CreateErrFn = handleIIDError
-	client.Opts = []internal.HTTPOption{internal.WithHeader("access_token_auth", "true")}
+	client.Opts = []internal.HTTPOption{
+		internal.WithHeader("access_token_auth", "true"),
+		internal.WithHeader("x-goog-api-client", internal.GetMetricsHeader(conf.Version)),
+	}
 	return &iidClient{
 		iidEndpoint: iidEndpoint,
 		httpClient:  client,
diff --git a/messaging/topic_mgt_test.go b/messaging/topic_mgt_test.go
index 15ea45d1..6d58114d 100644
--- a/messaging/topic_mgt_test.go
+++ b/messaging/topic_mgt_test.go
@@ -25,6 +25,7 @@ import (
 	"testing"
 
 	"firebase.google.com/go/v4/errorutils"
+	"firebase.google.com/go/v4/internal"
 )
 
 func TestSubscribe(t *testing.T) {
@@ -198,6 +199,10 @@ func checkIIDRequest(t *testing.T, b []byte, tr *http.Request, op string) {
 	if h := tr.Header.Get("Authorization"); h != "Bearer test-token" {
 		t.Errorf("Authorization = %q; want = %q", h, "Bearer test-token")
 	}
+	xGoogAPIClientHeader := internal.GetMetricsHeader(testMessagingConfig.Version)
+	if h := tr.Header.Get("x-goog-api-client"); h != xGoogAPIClientHeader {
+		t.Errorf("x-goog-api-client header = %q; want = %q", h, xGoogAPIClientHeader)
+	}
 }
 
 func checkTopicMgtResponse(t *testing.T, resp *TopicManagementResponse) {