diff --git a/go/vehicle-gateway/internal/identity/resolver.go b/go/vehicle-gateway/internal/identity/resolver.go
index c30b4f2c..9bb3cc1c 100644
--- a/go/vehicle-gateway/internal/identity/resolver.go
+++ b/go/vehicle-gateway/internal/identity/resolver.go
@@ -88,6 +88,13 @@ func (r *MySQLResolver) EnsureSchema(ctx context.Context) error {
 	if _, err := r.db.ExecContext(ctx, identityBindingTableSQL(r.table)); err != nil {
 		return err
 	}
+	for _, statement := range identityBindingAlterSQL(r.table) {
+		if _, err := r.db.ExecContext(ctx, statement); err != nil {
+			if !isDuplicateColumnError(err) {
+				return err
+			}
+		}
+	}
 	_, err := r.db.ExecContext(ctx, jt808RegistrationTableSQL)
 	return err
 }
@@ -101,6 +108,7 @@ func identityBindingTableSQL(table string) string {
   plate VARCHAR(32) NULL,
   phone VARCHAR(32) NULL,
   device_id VARCHAR(64) NULL,
+  oem VARCHAR(64) NULL,
   updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
   UNIQUE KEY uk_identity_plate (plate),
   UNIQUE KEY uk_identity_phone (phone),
@@ -108,6 +116,20 @@ func identityBindingTableSQL(table string) string {
 )`
 }
 
+func identityBindingAlterSQL(table string) []string {
+	if table == "" || !safeIdentifier(table) {
+		table = "vehicle_identity_binding"
+	}
+	return []string{
+		`ALTER TABLE ` + table + ` ADD COLUMN oem VARCHAR(64) NULL AFTER device_id`,
+	}
+}
+
+func isDuplicateColumnError(err error) bool {
+	text := strings.ToLower(strings.TrimSpace(fmt.Sprint(err)))
+	return strings.Contains(text, "duplicate column") || strings.Contains(text, "error 1060")
+}
+
 const jt808RegistrationTableSQL = `CREATE TABLE IF NOT EXISTS jt808_registration (
   phone VARCHAR(32) PRIMARY KEY,
   device_id VARCHAR(64) NULL,
diff --git a/go/vehicle-gateway/internal/identity/resolver_test.go b/go/vehicle-gateway/internal/identity/resolver_test.go
index 1972d42c..f83f3ce4 100644
--- a/go/vehicle-gateway/internal/identity/resolver_test.go
+++ b/go/vehicle-gateway/internal/identity/resolver_test.go
@@ -3,6 +3,7 @@ package identity
 import (
 	"context"
 	"database/sql"
+	"errors"
 	"strings"
 	"testing"
 	"time"
@@ -293,6 +294,27 @@ func TestMySQLResolverEnsuresMinimalIdentitySchema(t *testing.T) {
 	defer db.Close()
 	mock.ExpectExec("CREATE TABLE IF NOT EXISTS vehicle_identity_binding").
 		WillReturnResult(sqlmock.NewResult(0, 0))
+	mock.ExpectExec("ALTER TABLE vehicle_identity_binding ADD COLUMN oem").
+		WillReturnResult(sqlmock.NewResult(0, 0))
+	mock.ExpectExec("CREATE TABLE IF NOT EXISTS jt808_registration").
+		WillReturnResult(sqlmock.NewResult(0, 0))
+
+	resolver := NewMySQLResolver(db, "vehicle_identity_binding")
+	if err := resolver.EnsureSchema(context.Background()); err != nil {
+		t.Fatalf("EnsureSchema() error = %v", err)
+	}
+	if err := mock.ExpectationsWereMet(); err != nil {
+		t.Fatalf("sql expectations: %v", err)
+	}
+}
+
+func TestMySQLResolverIgnoresExistingOEMColumn(t *testing.T) {
+	db, mock := newMockDB(t)
+	defer db.Close()
+	mock.ExpectExec("CREATE TABLE IF NOT EXISTS vehicle_identity_binding").
+		WillReturnResult(sqlmock.NewResult(0, 0))
+	mock.ExpectExec("ALTER TABLE vehicle_identity_binding ADD COLUMN oem").
+		WillReturnError(errors.New("Error 1060 (42S21): Duplicate column name 'oem'"))
 	mock.ExpectExec("CREATE TABLE IF NOT EXISTS jt808_registration").
 		WillReturnResult(sqlmock.NewResult(0, 0))