diff --git a/backend/app/services/ml/allowlist.py b/backend/app/services/ml/allowlist.py
index dc8aeab..08a6ac7 100644
--- a/backend/app/services/ml/allowlist.py
+++ b/backend/app/services/ml/allowlist.py
@@ -9,7 +9,7 @@ from sqlalchemy import delete, select
 from sqlalchemy.dialects.postgresql import insert
 from sqlalchemy.ext.asyncio import AsyncSession
 
-from ...models import Tag, TagAllowlist, TagSuggestionRejection
+from ...models import MLSettings, Tag, TagAllowlist, TagSuggestionRejection
 from ...models.tag import image_tag
 from .aliases import AliasService
 
@@ -91,12 +91,25 @@ class AllowlistService:
         )
         await self.dismiss(image_id, tag_id)
 
+    async def _store_floor(self) -> float:
+        return (
+            await self.session.execute(
+                select(MLSettings.tagger_store_floor).where(MLSettings.id == 1)
+            )
+        ).scalar_one()
+
     async def update_threshold(
         self, tag_id: int, min_confidence: float
     ) -> None:
         row = await self.session.get(TagAllowlist, tag_id)
         if row is not None:
-            row.min_confidence = min_confidence
+            # An allowlist tag can't auto-apply more permissively than the
+            # ingest store floor — predictions below tagger_store_floor aren't
+            # stored, so a lower min_confidence would behave identically to the
+            # floor. Clamp so the stored threshold matches actual behavior
+            # (#764).
+            floor = await self._store_floor()
+            row.min_confidence = max(min_confidence, floor)
 
     async def remove(self, tag_id: int) -> None:
         await self.session.execute(
diff --git a/frontend/src/components/settings/AllowlistTable.vue b/frontend/src/components/settings/AllowlistTable.vue
index 9448125..2ac386d 100644
--- a/frontend/src/components/settings/AllowlistTable.vue
+++ b/frontend/src/components/settings/AllowlistTable.vue
@@ -10,7 +10,7 @@
         <v-text-field
           :model-value="item.min_confidence" type="number"
           density="compact" hide-details style="max-width: 100px;"
-          min="0.05" max="1" step="0.05"
+          :min="floor" max="1" step="0.05"
           @update:model-value="(v) => onThreshold(item.tag_id, v)"
         />
       </template>
@@ -25,23 +25,32 @@
 </template>
 
 <script setup>
-import { onMounted } from 'vue'
+import { computed, onMounted } from 'vue'
 import { useAllowlistStore } from '../../stores/allowlist.js'
+import { useMLStore } from '../../stores/ml.js'
 
 const store = useAllowlistStore()
+const ml = useMLStore()
+// min_confidence can't be set below the tagger store floor — predictions
+// below it aren't stored, so a lower threshold would behave identically to
+// the floor. The backend clamps too (#764).
+const floor = computed(() => ml.settings?.tagger_store_floor ?? 0.70)
 const headers = [
   { title: 'Tag', key: 'tag_name', sortable: true },
   { title: 'Kind', key: 'tag_kind', sortable: true, width: 110 },
   { title: 'Min confidence', key: 'min_confidence', sortable: false, width: 140 },
   { title: '', key: 'actions', sortable: false, width: 60 }
 ]
-onMounted(() => store.load())
+onMounted(() => {
+  store.load()
+  if (!ml.settings) ml.loadSettings()
+})
 
 let debounce = null
 function onThreshold(tagId, value) {
   if (debounce) clearTimeout(debounce)
   debounce = setTimeout(() => {
-    const v = parseFloat(value)
+    const v = Math.max(parseFloat(value), floor.value)
     if (v > 0 && v <= 1) store.updateThreshold(tagId, v)
   }, 500)
 }
diff --git a/tests/test_ml_allowlist.py b/tests/test_ml_allowlist.py
index a4c94bd..ad3298f 100644
--- a/tests/test_ml_allowlist.py
+++ b/tests/test_ml_allowlist.py
@@ -104,3 +104,17 @@ async def test_update_threshold_and_remove(db):
     assert abs(row.min_confidence - 0.80) < 1e-6
     await svc.remove(tag.id)
     assert await db.get(TagAllowlist, tag.id) is None
+
+
+@pytest.mark.asyncio
+async def test_update_threshold_clamped_to_store_floor(db):
+    # A min_confidence below the store floor (default 0.70) is clamped up —
+    # predictions below the floor aren't stored, so a lower threshold can't
+    # apply more permissively than the floor (#764).
+    tag = await TagService(db).find_or_create("Lowthr", TagKind.general)
+    svc = AllowlistService(db)
+    img = await _make_image(db)
+    await svc.accept(img.id, tag.id)
+    await svc.update_threshold(tag.id, 0.30)
+    row = await db.get(TagAllowlist, tag.id)
+    assert abs(row.min_confidence - 0.70) < 1e-6