diff --git a/cellular_capability_gsm.cc b/cellular_capability_gsm.cc
index 464d62b..1862e3e 100644
--- a/cellular_capability_gsm.cc
+++ b/cellular_capability_gsm.cc
@@ -19,17 +19,46 @@
 
 void CellularCapabilityGSM::InitProxies() {
   VLOG(2) << __func__;
-  // TODO(petkov): Move GSM-specific proxy ownership from Cellular to this.
-  cellular()->set_modem_gsm_card_proxy(
-      proxy_factory()->CreateModemGSMCardProxy(cellular(),
+  card_proxy_.reset(
+      proxy_factory()->CreateModemGSMCardProxy(this,
                                                cellular()->dbus_path(),
                                                cellular()->dbus_owner()));
+  // TODO(petkov): Move GSM-specific proxy ownership from Cellular to this.
   cellular()->set_modem_gsm_network_proxy(
       proxy_factory()->CreateModemGSMNetworkProxy(cellular(),
                                                   cellular()->dbus_path(),
                                                   cellular()->dbus_owner()));
 }
 
+void CellularCapabilityGSM::GetIdentifiers() {
+  VLOG(2) << __func__;
+  if (cellular()->imei().empty()) {
+    // TODO(petkov): Switch to asynchronous calls (crosbug.com/17583).
+    cellular()->set_imei(card_proxy_->GetIMEI());
+    VLOG(2) << "IMEI: " << cellular()->imei();
+  }
+  if (cellular()->imsi().empty()) {
+    // TODO(petkov): Switch to asynchronous calls (crosbug.com/17583).
+    cellular()->set_imsi(card_proxy_->GetIMSI());
+    VLOG(2) << "IMSI: " << cellular()->imsi();
+  }
+  if (cellular()->spn().empty()) {
+    // TODO(petkov): Switch to asynchronous calls (crosbug.com/17583).
+    try {
+      cellular()->set_spn(card_proxy_->GetSPN());
+      VLOG(2) << "SPN: " << cellular()->spn();
+    } catch (const DBus::Error e) {
+      // Some modems don't support this call so catch the exception explicitly.
+      LOG(WARNING) << "Unable to obtain SPN: " << e.what();
+    }
+  }
+  if (cellular()->mdn().empty()) {
+    // TODO(petkov): Switch to asynchronous calls (crosbug.com/17583).
+    cellular()->set_mdn(card_proxy_->GetMSISDN());
+    VLOG(2) << "MSISDN/MDN: " << cellular()->mdn();
+  }
+}
+
 void CellularCapabilityGSM::RequirePIN(
     const string &pin, bool require, Error */*error*/) {
   VLOG(2) << __func__ << "(" << pin << ", " << require << ")";
@@ -42,7 +71,7 @@
 void CellularCapabilityGSM::RequirePINTask(const string &pin, bool require) {
   VLOG(2) << __func__ << "(" << pin << ", " << require << ")";
   // TODO(petkov): Switch to asynchronous calls (crosbug.com/17583).
-  cellular()->modem_gsm_card_proxy()->EnablePIN(pin, require);
+  card_proxy_->EnablePIN(pin, require);
 }
 
 void CellularCapabilityGSM::EnterPIN(const string &pin, Error */*error*/) {
@@ -56,7 +85,7 @@
 void CellularCapabilityGSM::EnterPINTask(const string &pin) {
   VLOG(2) << __func__ << "(" << pin << ")";
   // TODO(petkov): Switch to asynchronous calls (crosbug.com/17583).
-  cellular()->modem_gsm_card_proxy()->SendPIN(pin);
+  card_proxy_->SendPIN(pin);
 }
 
 void CellularCapabilityGSM::UnblockPIN(
@@ -72,7 +101,7 @@
     const string &unblock_code, const string &pin) {
   VLOG(2) << __func__ << "(" << unblock_code << ", " << pin << ")";
   // TODO(petkov): Switch to asynchronous calls (crosbug.com/17583).
-  cellular()->modem_gsm_card_proxy()->SendPUK(unblock_code, pin);
+  card_proxy_->SendPUK(unblock_code, pin);
 }
 
 void CellularCapabilityGSM::ChangePIN(
@@ -88,7 +117,7 @@
     const string &old_pin, const string &new_pin) {
   VLOG(2) << __func__ << "(" << old_pin << ", " << new_pin << ")";
   // TODO(petkov): Switch to asynchronous calls (crosbug.com/17583).
-  cellular()->modem_gsm_card_proxy()->ChangePIN(old_pin, new_pin);
+  card_proxy_->ChangePIN(old_pin, new_pin);
 }
 
 }  // namespace shill