diff --git a/wifi/supplicant/1.4/Android.bp b/wifi/supplicant/1.4/Android.bp
index 0a039de..2867629 100644
--- a/wifi/supplicant/1.4/Android.bp
+++ b/wifi/supplicant/1.4/Android.bp
@@ -10,6 +10,7 @@
         "ISupplicantStaIface.hal",
         "ISupplicantStaNetwork.hal",
         "ISupplicantStaNetworkCallback.hal",
+        "ISupplicantStaIfaceCallback.hal",
     ],
     interfaces: [
         "android.hardware.wifi.supplicant@1.0",
diff --git a/wifi/supplicant/1.4/ISupplicantStaIface.hal b/wifi/supplicant/1.4/ISupplicantStaIface.hal
index 28ef912..68fd01d 100644
--- a/wifi/supplicant/1.4/ISupplicantStaIface.hal
+++ b/wifi/supplicant/1.4/ISupplicantStaIface.hal
@@ -17,6 +17,7 @@
 package android.hardware.wifi.supplicant@1.4;
 
 import @1.0::SupplicantStatus;
+import ISupplicantStaIfaceCallback;
 import @1.3::ISupplicantStaIface;
 
 /**
@@ -36,4 +37,22 @@
     getConnectionCapabilities_1_4()
         generates (SupplicantStatus status, ConnectionCapabilities capabilities);
 
+    /**
+     * Register for callbacks from this interface.
+     *
+     * These callbacks are invoked for events that are specific to this interface.
+     * Registration of multiple callback objects is supported. These objects must
+     * be automatically deleted when the corresponding client process is dead or
+     * if this interface is removed.
+     *
+     * @param callback An instance of the |ISupplicantStaIfaceCallback| HIDL
+     *        interface object.
+     * @return status Status of the operation.
+     *         Possible status codes:
+     *         |SupplicantStatusCode.SUCCESS|,
+     *         |SupplicantStatusCode.FAILURE_UNKNOWN|,
+     *         |SupplicantStatusCode.FAILURE_IFACE_INVALID|
+     */
+    registerCallback_1_4(ISupplicantStaIfaceCallback callback)
+        generates (SupplicantStatus status);
 };
diff --git a/wifi/supplicant/1.4/ISupplicantStaIfaceCallback.hal b/wifi/supplicant/1.4/ISupplicantStaIfaceCallback.hal
new file mode 100644
index 0000000..20bce34
--- /dev/null
+++ b/wifi/supplicant/1.4/ISupplicantStaIfaceCallback.hal
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.hardware.wifi.supplicant@1.4;
+
+import @1.3::ISupplicantStaIfaceCallback;
+import @1.0::ISupplicantStaIfaceCallback.State;
+import @1.0::Bssid;
+
+/**
+ * Callback Interface exposed by the supplicant service
+ * for each station mode interface (ISupplicantStaIface).
+ *
+ * Clients need to host an instance of this HIDL interface object and
+ * pass a reference of the object to the supplicant via the
+ * corresponding |ISupplicantStaIface.registerCallback_1_4| method.
+ */
+interface ISupplicantStaIfaceCallback extends @1.3::ISupplicantStaIfaceCallback {
+    /**
+     * Used to indicate a Hotspot 2.0 terms and conditions acceptance is requested from the user
+     * before allowing the device to get internet access.
+     *
+     * @param bssid BSSID of the access point.
+     * @param url URL of the T&C server.
+     */
+    oneway onHs20TermsAndConditionsAcceptanceRequestedNotification(Bssid bssid, string url);
+};
diff --git a/wifi/supplicant/1.4/vts/functional/supplicant_sta_iface_hidl_test.cpp b/wifi/supplicant/1.4/vts/functional/supplicant_sta_iface_hidl_test.cpp
index 5b9c750..fbf6445 100644
--- a/wifi/supplicant/1.4/vts/functional/supplicant_sta_iface_hidl_test.cpp
+++ b/wifi/supplicant/1.4/vts/functional/supplicant_sta_iface_hidl_test.cpp
@@ -22,6 +22,7 @@
 #include <android/hardware/wifi/supplicant/1.3/types.h>
 #include <android/hardware/wifi/supplicant/1.4/ISupplicant.h>
 #include <android/hardware/wifi/supplicant/1.4/ISupplicantStaIface.h>
+#include <android/hardware/wifi/supplicant/1.4/ISupplicantStaIfaceCallback.h>
 #include <android/hardware/wifi/supplicant/1.4/types.h>
 #include <gtest/gtest.h>
 #include <hidl/GtestPrinter.h>
@@ -32,13 +33,22 @@
 #include "supplicant_hidl_test_utils_1_4.h"
 
 using ::android::sp;
+using ::android::hardware::hidl_array;
+using ::android::hardware::hidl_string;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::Return;
 using ::android::hardware::Void;
 using ::android::hardware::wifi::supplicant::V1_0::SupplicantStatus;
 using ::android::hardware::wifi::supplicant::V1_0::SupplicantStatusCode;
-
+using ::android::hardware::wifi::supplicant::V1_2::DppAkm;
+using ::android::hardware::wifi::supplicant::V1_2::DppFailureCode;
+using ::android::hardware::wifi::supplicant::V1_2::DppNetRole;
+using ::android::hardware::wifi::supplicant::V1_2::DppProgressCode;
+using ::android::hardware::wifi::supplicant::V1_3::DppSuccessCode;
 using ::android::hardware::wifi::supplicant::V1_4::ConnectionCapabilities;
 using ::android::hardware::wifi::supplicant::V1_4::ISupplicant;
 using ::android::hardware::wifi::supplicant::V1_4::ISupplicantStaIface;
+using ::android::hardware::wifi::supplicant::V1_4::ISupplicantStaIfaceCallback;
 
 class SupplicantStaIfaceHidlTest : public SupplicantHidlTestBaseV1_4 {
    public:
@@ -53,6 +63,133 @@
     sp<ISupplicantStaIface> sta_iface_;
 };
 
+class IfaceCallback : public ISupplicantStaIfaceCallback {
+    Return<void> onNetworkAdded(uint32_t /* id */) override { return Void(); }
+    Return<void> onNetworkRemoved(uint32_t /* id */) override { return Void(); }
+    Return<void> onStateChanged(
+        ISupplicantStaIfaceCallback::State /* newState */,
+        const hidl_array<uint8_t, 6>& /*bssid */, uint32_t /* id */,
+        const hidl_vec<uint8_t>& /* ssid */) override {
+        return Void();
+    }
+    Return<void> onAnqpQueryDone(
+        const hidl_array<uint8_t, 6>& /* bssid */,
+        const ISupplicantStaIfaceCallback::AnqpData& /* data */,
+        const ISupplicantStaIfaceCallback::Hs20AnqpData& /* hs20Data */)
+        override {
+        return Void();
+    }
+    virtual Return<void> onHs20IconQueryDone(
+        const hidl_array<uint8_t, 6>& /* bssid */,
+        const hidl_string& /* fileName */,
+        const hidl_vec<uint8_t>& /* data */) override {
+        return Void();
+    }
+    virtual Return<void> onHs20SubscriptionRemediation(
+        const hidl_array<uint8_t, 6>& /* bssid */,
+        ISupplicantStaIfaceCallback::OsuMethod /* osuMethod */,
+        const hidl_string& /* url*/) override {
+        return Void();
+    }
+    Return<void> onHs20TermsAndConditionsAcceptanceRequestedNotification(
+        const hidl_array<uint8_t, 6>& /* bssid */,
+        const hidl_string& /* url */) override {
+        return Void();
+    }
+    Return<void> onHs20DeauthImminentNotice(
+        const hidl_array<uint8_t, 6>& /* bssid */, uint32_t /* reasonCode */,
+        uint32_t /* reAuthDelayInSec */,
+        const hidl_string& /* url */) override {
+        return Void();
+    }
+    Return<void> onDisconnected(const hidl_array<uint8_t, 6>& /* bssid */,
+                                bool /* locallyGenerated */,
+                                ISupplicantStaIfaceCallback::ReasonCode
+                                /* reasonCode */) override {
+        return Void();
+    }
+    Return<void> onAssociationRejected(
+        const hidl_array<uint8_t, 6>& /* bssid */,
+        ISupplicantStaIfaceCallback::StatusCode /* statusCode */,
+        bool /*timedOut */) override {
+        return Void();
+    }
+    Return<void> onAuthenticationTimeout(
+        const hidl_array<uint8_t, 6>& /* bssid */) override {
+        return Void();
+    }
+    Return<void> onBssidChanged(
+        ISupplicantStaIfaceCallback::BssidChangeReason /* reason */,
+        const hidl_array<uint8_t, 6>& /* bssid */) override {
+        return Void();
+    }
+    Return<void> onEapFailure() override { return Void(); }
+    Return<void> onEapFailure_1_1(
+        ISupplicantStaIfaceCallback::EapErrorCode /* eapErrorCode */) override {
+        return Void();
+    }
+    Return<void> onEapFailure_1_3(uint32_t /* eapErrorCode */) override {
+        return Void();
+    }
+    Return<void> onWpsEventSuccess() override { return Void(); }
+    Return<void> onWpsEventFail(
+        const hidl_array<uint8_t, 6>& /* bssid */,
+        ISupplicantStaIfaceCallback::WpsConfigError /* configError */,
+        ISupplicantStaIfaceCallback::WpsErrorIndication /* errorInd */)
+        override {
+        return Void();
+    }
+    Return<void> onWpsEventPbcOverlap() override { return Void(); }
+    Return<void> onExtRadioWorkStart(uint32_t /* id */) override {
+        return Void();
+    }
+    Return<void> onExtRadioWorkTimeout(uint32_t /* id*/) override {
+        return Void();
+    }
+    Return<void> onDppSuccessConfigReceived(
+        const hidl_vec<uint8_t>& /* ssid */, const hidl_string& /* password */,
+        const hidl_array<uint8_t, 32>& /* psk */,
+        DppAkm /* securityAkm */) override {
+        return Void();
+    }
+    Return<void> onDppSuccessConfigSent() override { return Void(); }
+    Return<void> onDppProgress(DppProgressCode /* code */) override {
+        return Void();
+    }
+    Return<void> onDppFailure(DppFailureCode /* code */) override {
+        return Void();
+    }
+    Return<void> onDppSuccess(DppSuccessCode /* code */) override {
+        return Void();
+    }
+    Return<void> onDppProgress_1_3(
+        ::android::hardware::wifi::supplicant::V1_3::DppProgressCode /* code */)
+        override {
+        return Void();
+    }
+    Return<void> onDppFailure_1_3(
+        ::android::hardware::wifi::supplicant::V1_3::DppFailureCode /* code */,
+        const hidl_string& /* ssid */, const hidl_string& /* channelList */,
+        const hidl_vec<uint16_t>& /* bandList */) override {
+        return Void();
+    }
+    Return<void> onPmkCacheAdded(
+        int64_t /* expirationTimeInSec */,
+        const hidl_vec<uint8_t>& /* serializedEntry */) override {
+        return Void();
+    }
+    Return<void> onBssTmHandlingDone(
+        const ISupplicantStaIfaceCallback::BssTmData& /* data */) override {
+        return Void();
+    }
+    Return<void> onStateChanged_1_3(
+        ISupplicantStaIfaceCallback::State /* newState */,
+        const hidl_array<uint8_t, 6>& /*bssid */, uint32_t /* id */,
+        const hidl_vec<uint8_t>& /* ssid */, bool /* filsHlpSent */) override {
+        return Void();
+    }
+};
+
 /*
  * getConnectionCapabilities_1_4
  */
@@ -64,6 +201,16 @@
         });
 }
 
+/*
+ * RegisterCallback_1_4
+ */
+TEST_P(SupplicantStaIfaceHidlTest, RegisterCallback_1_4) {
+    sta_iface_->registerCallback_1_4(
+        new IfaceCallback(), [](const SupplicantStatus& status) {
+            EXPECT_EQ(SupplicantStatusCode::SUCCESS, status.code);
+        });
+}
+
 GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(SupplicantStaIfaceHidlTest);
 INSTANTIATE_TEST_CASE_P(
     PerInstance, SupplicantStaIfaceHidlTest,