diff --git a/.github/workflows/esp32p4-smv-injector.yml b/.github/workflows/esp32p4-smv-injector.yml
index 28d37bd06..96a2caefd 100644
--- a/.github/workflows/esp32p4-smv-injector.yml
+++ b/.github/workflows/esp32p4-smv-injector.yml
@@ -157,6 +157,9 @@ jobs:
           grep -qx 'CONFIG_AR_PTP_DOMAIN=0' sdkconfig
           grep -qx 'CONFIG_AR_PTP_TRANSPORT_SPECIFIC=0' sdkconfig
           grep -qx 'CONFIG_AR_PTP_RESPOND_PDELAY=y' sdkconfig
+          grep -qx 'CONFIG_AR_PTP_VLAN=y' sdkconfig
+          grep -qx 'CONFIG_AR_PTP_VLAN_ID=0' sdkconfig
+          grep -qx 'CONFIG_AR_PTP_VLAN_PRIORITY=4' sdkconfig
           grep -qx 'CONFIG_AR_PTP_SYNC_INTERVAL_MS=1000' sdkconfig
           grep -qx 'CONFIG_AR_PTP_ANNOUNCE_INTERVAL_MS=1000' sdkconfig
           echo 'Production timing profile: PASS · serialized shared EMAC TX · PTP-P2 LAB_SOURCE · HW timestamp adapter compiled'
diff --git a/apps/arstack_studio/qml/PtpExpertPanel.qml b/apps/arstack_studio/qml/PtpExpertPanel.qml
index 67f1cd4fc..61a5885e8 100644
--- a/apps/arstack_studio/qml/PtpExpertPanel.qml
+++ b/apps/arstack_studio/qml/PtpExpertPanel.qml
@@ -545,8 +545,8 @@ SurfacePanel {
                     NumericField { id: announceField; visible: modeCombo.currentIndex !== 0; theme: panel.theme; monoFont: panel.uiFont; text: "1000"; validator: IntValidator { bottom: 100; top: 10000 } }
                     Label { text: "Sync interval (ms)"; visible: modeCombo.currentIndex !== 0; color: panel.theme.muted; font.family: panel.uiFont; font.pixelSize: 9 }
                     NumericField { id: syncField; visible: modeCombo.currentIndex !== 0; theme: panel.theme; monoFont: panel.uiFont; text: "1000"; validator: IntValidator { bottom: 20; top: 5000 } }
-                    StudioDarkCheckBox { id: vlanCheck; theme: panel.theme; uiFont: panel.uiFont; text: "VLAN" }
-                    NumericField { id: vlanField; enabled: vlanCheck.checked; theme: panel.theme; monoFont: panel.uiFont; text: "100"; validator: IntValidator { bottom: 1; top: 4094 } }
+                    StudioDarkCheckBox { id: vlanCheck; theme: panel.theme; uiFont: panel.uiFont; text: "VLAN"; checked: true }
+                    NumericField { id: vlanField; enabled: vlanCheck.checked; theme: panel.theme; monoFont: panel.uiFont; text: "0"; validator: IntValidator { bottom: 0; top: 4094 } }
                     Label { text: "VLAN PCP"; color: panel.theme.muted; font.family: panel.uiFont; font.pixelSize: 9 }
                     NumericField { id: pcpField; enabled: vlanCheck.checked; theme: panel.theme; monoFont: panel.uiFont; text: "4"; validator: IntValidator { bottom: 0; top: 7 } }
                     Label {
diff --git a/apps/arstack_studio/src/DeviceController.cpp b/apps/arstack_studio/src/DeviceController.cpp
index 94dbf721a..942e1031e 100644
--- a/apps/arstack_studio/src/DeviceController.cpp
+++ b/apps/arstack_studio/src/DeviceController.cpp
@@ -1350,8 +1350,7 @@ QString DeviceController::ptpConfigCommand(const QVariantMap& profile) {
         !parse("vlanPriority", 7U, pcp) ||
         !parse("announceIntervalMs", 10000U, announce) ||
         !parse("syncIntervalMs", 5000U, sync) ||
-        announce < 100U || sync < 20U ||
-        (profile.value(QStringLiteral("vlanEnabled")).toBool() && vlan == 0U)) {
+        announce < 100U || sync < 20U) {
         return {};
     }
     return QStringLiteral("PTP CONFIG %1 %2 %3 %4 %5 %6 %7 %8")
diff --git a/embedded/esp32p4_smv_injector/main/Kconfig.projbuild b/embedded/esp32p4_smv_injector/main/Kconfig.projbuild
index b7188d5da..06e88cd20 100644
--- a/embedded/esp32p4_smv_injector/main/Kconfig.projbuild
+++ b/embedded/esp32p4_smv_injector/main/Kconfig.projbuild
@@ -134,14 +134,14 @@ config AR_PTP_PORT_NUMBER
     depends on AR_PTP_LAB_TX
 
 config AR_PTP_VLAN
-    bool "Tag PTP traffic with IEEE 802.1Q VLAN"
-    default n
+    bool "Tag PTP traffic with IEEE 802.1Q VLAN (Power Profile PCP4/VID0)"
+    default y
     depends on AR_PTP_LAB_TX
 
 config AR_PTP_VLAN_ID
-    int "PTP VLAN ID"
-    range 1 4094
-    default 100
+    int "PTP VLAN ID (0 means 802.1Q priority tag)"
+    range 0 4094
+    default 0
     depends on AR_PTP_LAB_TX && AR_PTP_VLAN
 
 config AR_PTP_VLAN_PRIORITY
diff --git a/embedded/esp32p4_smv_injector/sdkconfig.defaults b/embedded/esp32p4_smv_injector/sdkconfig.defaults
index 95776790c..41a7a0580 100644
--- a/embedded/esp32p4_smv_injector/sdkconfig.defaults
+++ b/embedded/esp32p4_smv_injector/sdkconfig.defaults
@@ -28,7 +28,9 @@ CONFIG_AR_PTP_OPERATING_ROLE=0
 CONFIG_AR_PTP_DOMAIN=0
 CONFIG_AR_PTP_TRANSPORT_SPECIFIC=0
 CONFIG_AR_PTP_PORT_NUMBER=1
-# CONFIG_AR_PTP_VLAN is not set
+CONFIG_AR_PTP_VLAN=y
+CONFIG_AR_PTP_VLAN_ID=0
+CONFIG_AR_PTP_VLAN_PRIORITY=4
 CONFIG_AR_PTP_ANNOUNCE_INTERVAL_MS=1000
 CONFIG_AR_PTP_SYNC_INTERVAL_MS=1000
 CONFIG_AR_PTP_RESPOND_PDELAY=y
diff --git a/include/ariec61850/time_sync/ptp_runtime.hpp b/include/ariec61850/time_sync/ptp_runtime.hpp
index 51e0a2554..9284dc811 100644
--- a/include/ariec61850/time_sync/ptp_runtime.hpp
+++ b/include/ariec61850/time_sync/ptp_runtime.hpp
@@ -190,9 +190,10 @@ class PtpPublisherRuntime final {
             error = "VLAN priority must be 0..7";
             return false;
         }
-        if (options.vlan_id.has_value() &&
-            (*options.vlan_id == 0U || *options.vlan_id > 4094U)) {
-            error = "VLAN ID must be 1..4094";
+        // IEEE 802.1Q priority-tagged VLAN 0 / PCP 4 is the Power
+        // Utility Profile default. 4095 is reserved; VID 0 is valid.
+        if (options.vlan_id.has_value() && *options.vlan_id > 4094U) {
+            error = "VLAN ID must be 0..4094";
             return false;
         }
         if (options.port_number == 0U) {
diff --git a/tests/test_ptp_power_profile.cpp b/tests/test_ptp_power_profile.cpp
index f76527391..f1d10910d 100644
--- a/tests/test_ptp_power_profile.cpp
+++ b/tests/test_ptp_power_profile.cpp
@@ -131,6 +131,31 @@ void check_source_heartbeat_freshness_and_time_provenance() {
     explicit_offset.stop();
 }
 
+void check_priority_tagged_power_profile_wire() {
+    auto options = make_source();
+    options.vlan_id = std::uint16_t{0U};
+    options.vlan_priority = 4U;
+    std::string error;
+    REQUIRE(PtpPublisherRuntime::validate_options(options, error));
+    PtpPublisherRuntime source{options};
+    REQUIRE(source.start());
+    const auto announce = source.prepare_announce(PtpTimestamp{1000U, 0U});
+    REQUIRE(announce.has_value());
+    const auto& raw = announce->ethernet_frame;
+    REQUIRE(raw.size() > 18U);
+    REQUIRE(raw[12] == 0x81U && raw[13] == 0x00U);
+    REQUIRE(raw[14] == 0x80U && raw[15] == 0x00U); // PCP4, VID0
+    REQUIRE(raw[16] == 0x88U && raw[17] == 0xF7U);
+    PtpFrame parsed{};
+    REQUIRE(PtpCodec::try_parse_ethernet_frame(raw, parsed));
+    REQUIRE(parsed.vlan_id.has_value());
+    REQUIRE(*parsed.vlan_id == static_cast<std::uint16_t>(0U));
+    REQUIRE(parsed.header.message_type == PtpMessageType::announce);
+    source.stop();
+    options.vlan_id = std::uint16_t{4095U};
+    REQUIRE(!PtpPublisherRuntime::validate_options(options, error));
+}
+
 void check_ptp_wire_sequence_and_identity() {
     auto options = make_source();
     constexpr std::uint8_t domain = 93U; // supported alternate network domain
@@ -309,6 +334,7 @@ int main() {
         check_source_readiness_requires_fresh_wire_proof();
         check_source_heartbeat_freshness_and_time_provenance();
         check_ptp_wire_sequence_and_identity();
+        check_priority_tagged_power_profile_wire();
         check_vlan_encoding_remains_configurable();
         check_tai_seed_and_truthful_time_properties();
         std::cout << "PTP Power Profile wire and configuration checks passed\n";