diff --git a/src/app/portfolio/[slug]/components/PropertyTable.tsx b/src/app/portfolio/[slug]/components/PropertyTable.tsx
index 6cbf399c..92419d1a 100644
--- a/src/app/portfolio/[slug]/components/PropertyTable.tsx
+++ b/src/app/portfolio/[slug]/components/PropertyTable.tsx
@@ -327,6 +327,21 @@ export default function PropertyTable({
   // Row selection for bulk tagging — keyed by property id (see DataTable getRowId).
   const [rowSelection, setRowSelection] = useState<RowSelectionState>({});
   const selectedIds = Object.keys(rowSelection).filter((id) => rowSelection[id]);
+  // Deliberate "select all matching" escalation (whole set, not just loaded rows).
+  const [selectAllMatching, setSelectAllMatching] = useState(false);
+
+  const clearSelection = () => {
+    setRowSelection({});
+    setSelectAllMatching(false);
+  };
+  // Any manual checkbox change drops the all-matching escalation back to the
+  // explicit (possibly now-smaller) row selection.
+  const handleRowSelectionChange = (
+    updater: Updater<RowSelectionState>,
+  ) => {
+    setSelectAllMatching(false);
+    setRowSelection(updater);
+  };
 
   // Bulk-tag flows launched from the Tags menu: a contextual assign/remove mode,
   // and the file-upload modal.
@@ -456,6 +471,16 @@ export default function PropertyTable({
   // loaded rows (cheap; avoids a hook per project convention): exact for a
   // fully-loaded portfolio, a floor when more rows lazy-load beyond view.
   const unmodelledInView = tableData.filter((p) => p.planId == null).length;
+
+  // Bulk-select scope: how many properties match the current view, whether every
+  // loaded row is ticked, and whether more match than are loaded (so "select all
+  // matching" is worth offering). matchingCount is filtered-total when a filter
+  // is active, else the whole portfolio.
+  const matchingCount = hasActiveFilters ? filteredTotal : totalCount;
+  const allLoadedSelected =
+    selectedIds.length > 0 && selectedIds.length === tableData.length;
+  const moreMatchThanLoaded = tableData.length < matchingCount;
+
   // The not-modelled banner owns the Run-modelling CTA in this state, so the
   // toolbar must NOT also show one — otherwise two identical navy buttons appear.
   const showModelNudge =
@@ -477,7 +502,7 @@ export default function PropertyTable({
     if (pagination.pageIndex !== 0)
       setPagination((p) => ({ ...p, pageIndex: 0 }));
     // The selection is filter-scoped — a changed filter invalidates it.
-    if (selectedIds.length > 0) setRowSelection({});
+    if (selectedIds.length > 0 || selectAllMatching) clearSelection();
   }
 
   const [isFetchingMore, setIsFetchingMore] = useState(false);
@@ -586,11 +611,13 @@ export default function PropertyTable({
               properties
             </span>
           )}
-          {selectedIds.length > 0 && (
+          {(selectedIds.length > 0 || selectAllMatching) && (
             <span className="inline-flex items-center gap-1.5 rounded-full border border-brandmidblue/30 bg-brandlightblue/50 px-2 py-0.5 text-xs font-semibold text-brandblue">
-              {selectedIds.length.toLocaleString()} selected
+              {selectAllMatching
+                ? `All ${matchingCount.toLocaleString()} selected`
+                : `${selectedIds.length.toLocaleString()} selected`}
               <button
-                onClick={() => setRowSelection({})}
+                onClick={clearSelection}
                 className="text-brandmidblue hover:text-brandblue"
               >
                 Clear
@@ -709,11 +736,11 @@ export default function PropertyTable({
           <TagsMenu
             onUpload={() => setTagUploadOpen(true)}
             onAssign={() => {
-              setRowSelection({});
+              clearSelection();
               setTagMode("assign");
             }}
             onRemove={() => {
-              setRowSelection({});
+              clearSelection();
               setTagMode("remove");
             }}
           />
@@ -842,13 +869,17 @@ export default function PropertyTable({
           portfolioId={portfolioId}
           mode={tagMode}
           selectedIds={selectedIds}
+          selectAllMatching={selectAllMatching}
           hasActiveFilters={hasActiveFilters}
           filterGroups={allFilterGroups}
-          filteredTotal={filteredTotal}
-          totalCount={totalCount}
+          matchingCount={matchingCount}
+          allLoadedSelected={allLoadedSelected}
+          moreMatchThanLoaded={moreMatchThanLoaded}
+          onSelectAllMatching={() => setSelectAllMatching(true)}
+          onClearSelection={clearSelection}
           onClose={() => {
             setTagMode(null);
-            setRowSelection({});
+            clearSelection();
           }}
         />
       )}
@@ -979,11 +1010,7 @@ export default function PropertyTable({
                 setPagination as (updater: Updater<PaginationState>) => void
               }
               rowSelection={rowSelection}
-              onRowSelectionChange={
-                setRowSelection as (
-                  updater: Updater<RowSelectionState>,
-                ) => void
-              }
+              onRowSelectionChange={handleRowSelectionChange}
             />
           )}
         </div>
diff --git a/src/app/portfolio/[slug]/components/TagActionBar.tsx b/src/app/portfolio/[slug]/components/TagActionBar.tsx
index a5c80771..eb960282 100644
--- a/src/app/portfolio/[slug]/components/TagActionBar.tsx
+++ b/src/app/portfolio/[slug]/components/TagActionBar.tsx
@@ -19,28 +19,37 @@ export type TagMode = "assign" | "remove";
 
 /**
  * The contextual strip shown while assigning or removing a tag in bulk
- * (ADR-0013). Its target follows the live table state: the row selection if any,
- * else every property matching the active filter, else the whole portfolio —
- * so ticking rows or changing filters re-scopes it in place. Picking a tag adds
- * (assign) or deletes (remove) memberships server-side and reports the count.
+ * (ADR-0013). The target is explicit: the ticked rows, or — after ticking every
+ * loaded row — "all N matching", which the user escalates to deliberately and
+ * which resolves the whole matching set server-side (not just the loaded page).
+ * With nothing selected there is no target, so a tag can't be applied by
+ * accident. Picking a tag adds/removes memberships and reports the count.
  */
 export function TagActionBar({
   portfolioId,
   mode,
   selectedIds,
+  selectAllMatching,
   hasActiveFilters,
   filterGroups,
-  filteredTotal,
-  totalCount,
+  matchingCount,
+  allLoadedSelected,
+  moreMatchThanLoaded,
+  onSelectAllMatching,
+  onClearSelection,
   onClose,
 }: {
   portfolioId: string;
   mode: TagMode;
   selectedIds: string[];
+  selectAllMatching: boolean;
   hasActiveFilters: boolean;
   filterGroups: FilterGroups;
-  filteredTotal: number;
-  totalCount: number;
+  matchingCount: number;
+  allLoadedSelected: boolean;
+  moreMatchThanLoaded: boolean;
+  onSelectAllMatching: () => void;
+  onClearSelection: () => void;
   onClose: () => void;
 }) {
   const { data: tags = [] } = usePortfolioTags(portfolioId);
@@ -51,25 +60,34 @@ export function TagActionBar({
   const verb = mode === "assign" ? "Assign" : "Remove";
   const prep = mode === "assign" ? "to" : "from";
 
-  // Target precedence: explicit selection → active filter set → whole portfolio.
-  const target =
-    selectedIds.length > 0
+  // The current target — explicit selection only (no implicit "all"). Selecting
+  // all matching is a deliberate escalation that switches to the filter path.
+  type Target = {
+    body:
+      | { mode: "properties"; propertyIds: string[] }
+      | { mode: "filter"; filterGroups: FilterGroups };
+    label: string;
+  };
+  const target: Target | null = selectAllMatching
+    ? {
+        body: {
+          mode: "filter",
+          filterGroups: hasActiveFilters ? filterGroups : [],
+        },
+        label: hasActiveFilters
+          ? `all ${matchingCount.toLocaleString()} matching your filter`
+          : `all ${matchingCount.toLocaleString()} properties`,
+      }
+    : selectedIds.length > 0
       ? {
-          body: { mode: "properties" as const, propertyIds: selectedIds },
+          body: { mode: "properties", propertyIds: selectedIds },
           label: `${selectedIds.length.toLocaleString()} selected propert${selectedIds.length === 1 ? "y" : "ies"}`,
         }
-      : hasActiveFilters
-        ? {
-            body: { mode: "filter" as const, filterGroups },
-            label: `all ${filteredTotal.toLocaleString()} matching your filters`,
-          }
-        : {
-            body: { mode: "filter" as const, filterGroups: [] as FilterGroups },
-            label: `all ${totalCount.toLocaleString()} properties`,
-          };
+      : null;
 
   const apply = useMutation<{ changed: number }, Error, Tag>({
     mutationFn: async (tag) => {
+      if (!target) throw new Error("Select some properties first");
       const res = await fetch(
         `/api/portfolio/${portfolioId}/tags/${tag.id}/assignments`,
         {
@@ -91,19 +109,50 @@ export function TagActionBar({
     onError: (e) => setResult(e.message),
   });
 
+  const showEscalate =
+    !selectAllMatching && allLoadedSelected && moreMatchThanLoaded;
+
   return (
     <div className="mb-3 flex flex-wrap items-center gap-2.5 rounded-lg border border-brandmidblue/30 bg-brandlightblue/40 px-3 py-2">
       <span className="text-xs font-bold text-brandblue">{verb} a tag</span>
+
       <span className="text-xs text-slate-600">
-        {prep} <span className="font-semibold text-brandblue">{target.label}</span>
-        <span className="text-slate-400"> — tick rows or apply filters to change this</span>
+        {target ? (
+          <>
+            {prep}{" "}
+            <span className="font-semibold text-brandblue">{target.label}</span>
+          </>
+        ) : (
+          <span className="text-slate-500">
+            Tick properties to {mode === "assign" ? "tag" : "untag"} them
+          </span>
+        )}
       </span>
 
+      {/* Deliberate escalation to the whole matching set (Gmail pattern). */}
+      {showEscalate && (
+        <button
+          onClick={onSelectAllMatching}
+          className="text-xs font-semibold text-brandmidblue underline-offset-2 hover:underline"
+        >
+          Select all {matchingCount.toLocaleString()}
+          {hasActiveFilters ? " matching" : ""}
+        </button>
+      )}
+      {selectAllMatching && (
+        <button
+          onClick={onClearSelection}
+          className="text-xs font-semibold text-brandmidblue underline-offset-2 hover:underline"
+        >
+          Clear selection
+        </button>
+      )}
+
       <DropdownMenu>
         <DropdownMenuTrigger asChild>
           <button
-            disabled={apply.isLoading}
-            className="inline-flex items-center gap-1.5 rounded-lg bg-primary px-3 py-1.5 text-xs font-semibold text-white transition hover:opacity-90 disabled:opacity-50"
+            disabled={apply.isLoading || !target}
+            className="inline-flex items-center gap-1.5 rounded-lg bg-primary px-3 py-1.5 text-xs font-semibold text-white transition hover:opacity-90 disabled:cursor-not-allowed disabled:opacity-40"
           >
             {apply.isLoading ? "Applying…" : "Choose a tag"}
             <ChevronDownIcon className="h-3.5 w-3.5 opacity-70" />