diff --git a/src/aare/gui/panels/data_collection_settings.py b/src/aare/gui/panels/data_collection_settings.py
index 7266597e..b3a57737 100644
--- a/src/aare/gui/panels/data_collection_settings.py
+++ b/src/aare/gui/panels/data_collection_settings.py
@@ -19,6 +19,7 @@ from PySide6.QtWidgets import (
 from aare.gui.panels.file_path_panel import FilePathPanel
 from aare.gui.panels.fluorescence_data_collection import FluorescenceDataCollectionPanel
 from aare.gui.panels.manual_sample_panel import ManualSamplePanel
+from aare.gui.panels.monochromator_panel import ENERGY_MAX_KEV, ENERGY_MIN_KEV, ENERGY_RANGE_TIP
 from aare.gui.panels.raster_data_collection import RasterDataCollectionPanel
 from aare.gui.panels.rotation_data_collection import RotationDataCollectionPanel
 from aare.gui.panels.smart_rotation_panel import SimpleRotationSettingsPanel
@@ -111,7 +112,8 @@ class DataCollectionSettings(QFrame):
         # energy without leaving the experiment configuration.
         self.energy_spin = QDoubleSpinBox(parent=self)
         self.energy_spin.setDecimals(3)
-        self.energy_spin.setRange(1.0, 30.0)
+        self.energy_spin.setRange(ENERGY_MIN_KEV, ENERGY_MAX_KEV)
+        self.energy_spin.setToolTip(ENERGY_RANGE_TIP)
         self.energy_spin.setSingleStep(0.1)
         self.energy_spin.setValue(12.0)
         # Pending color (same movestate QSS as the value fields) from edit
diff --git a/src/aare/gui/panels/monochromator_panel.py b/src/aare/gui/panels/monochromator_panel.py
index 58bbcf33..15710743 100644
--- a/src/aare/gui/panels/monochromator_panel.py
+++ b/src/aare/gui/panels/monochromator_panel.py
@@ -5,6 +5,16 @@ from PySide6.QtWidgets import QDoubleSpinBox, QGridLayout, QLabel, QPushButton,
 from aare.gui.styles import THEME_SUNRISE, status_colors
 from aare.gui.widgets.title_label import TitleLabel
 
+# TODO: placeholder range (was an arbitrary 1-30; nothing downstream validates —
+# daq.change_energy forwards straight to bec) — confirm the real monochromator
+# limits with the Beamline Scientist. Shared by both Set Energy rows.
+ENERGY_MIN_KEV = 4.0
+ENERGY_MAX_KEV = 20.0
+ENERGY_RANGE_TIP = (
+    f"Minimum: {ENERGY_MIN_KEV:.3f} keV\nMaximum: {ENERGY_MAX_KEV:.3f} keV\n"
+    "Range to be confirmed with Beamline Scientist"
+)
+
 
 class MonochromatorPanel(QWidget):
     mono_pitch_scan = Signal()
@@ -43,7 +53,8 @@ class MonochromatorPanel(QWidget):
 
         self.energy_spin = QDoubleSpinBox(parent=self)
         self.energy_spin.setDecimals(3)
-        self.energy_spin.setRange(1.0, 30.0)
+        self.energy_spin.setRange(ENERGY_MIN_KEV, ENERGY_MAX_KEV)
+        self.energy_spin.setToolTip(ENERGY_RANGE_TIP)
         self.energy_spin.setSingleStep(0.1)
         self.energy_spin.setValue(12.0)
         grid_layout.addWidget(self.energy_spin, 3, 1)
diff --git a/tests/unit/gui/test_data_collection_settings.py b/tests/unit/gui/test_data_collection_settings.py
index 6e59b889..7d400c4e 100644
--- a/tests/unit/gui/test_data_collection_settings.py
+++ b/tests/unit/gui/test_data_collection_settings.py
@@ -351,6 +351,11 @@ def test_db_override_source_toggle_clears_pending(qapp, qtbot):
 
 
 def test_energy_spin_pending_until_change_energy(settings_panel):
+    # same placeholder limits as the Beamline setup row (shared constants)
+    assert settings_panel.energy_spin.minimum() == 4.0
+    assert settings_panel.energy_spin.maximum() == 20.0
+    assert "Beamline Scientist" in settings_panel.energy_spin.toolTip()
+
     box = settings_panel.energy_spin.lineEdit()
     settings_panel.energy_spin.setValue(12.4)
     assert box.property("movestate") == "pending"
diff --git a/tests/unit/gui/test_monochromator_panel.py b/tests/unit/gui/test_monochromator_panel.py
index dabd2d2a..5c4bf1f5 100644
--- a/tests/unit/gui/test_monochromator_panel.py
+++ b/tests/unit/gui/test_monochromator_panel.py
@@ -36,3 +36,13 @@ def test_fast_shutter_row(qtbot, daq_status_factory):
         panel.open_shutter_button.click()
     with qtbot.waitSignal(panel.close_shutter, timeout=1000):
         panel.close_shutter_button.click()
+
+
+def test_energy_spin_placeholder_limits(qtbot):
+    # 4-20 keV is a placeholder pending Beamline Scientist confirmation; the
+    # tooltip must say so because nothing downstream validates the request.
+    panel = MonochromatorPanel()
+    qtbot.addWidget(panel)
+    assert panel.energy_spin.minimum() == 4.0
+    assert panel.energy_spin.maximum() == 20.0
+    assert "Beamline Scientist" in panel.energy_spin.toolTip()