diff --git a/frontend/src/desktop/createDesktopSurface.js b/frontend/src/desktop/createDesktopSurface.js
index 0ca4a33..2b1dd9a 100644
--- a/frontend/src/desktop/createDesktopSurface.js
+++ b/frontend/src/desktop/createDesktopSurface.js
@@ -84,12 +84,13 @@ const createDesktopSurface = ({
   const sidebarToggle = renderSidebarToggle ? renderSidebarToggle() : null;
   const detail = detailOpen && detailProps
     ? (() => {
-        const { onClose, onOpenPreview, ...restDetailProps } = detailProps;
+        const { onClose, onOpenPreview, tags: tagOptions, ...restDetailProps } = detailProps;
         return (
           <DocumentViewerPanel
             variant="sidebar"
             onCollapsePanel={onClose}
             onMaximizePanel={onOpenPreview}
+            tagOptions={tagOptions}
             {...restDetailProps}
           />
         );
diff --git a/frontend/src/documents/DocumentSummarySection.jsx b/frontend/src/documents/DocumentSummarySection.jsx
index b040c32..5793167 100644
--- a/frontend/src/documents/DocumentSummarySection.jsx
+++ b/frontend/src/documents/DocumentSummarySection.jsx
@@ -1,6 +1,6 @@
 import React, { useCallback, useEffect, useMemo, useState } from 'react';
 import { EditIcon, IconX, PlusIcon } from '../ui/icons';
-import QuickAddMenu from '../ui/QuickAddMenu';
+import SelectionAssignmentMenu from './SelectionAssignmentMenu';
 import { getTagColorStyle } from '../utils/colors';
 import {
   formatDate,
@@ -34,6 +34,29 @@ export const buildCorrespondentOptions = (entries = []) => {
 
 const normalizeOptions = (options) => (Array.isArray(options) ? options : []);
 
+const normalizeQuickAddOption = (option) => {
+  if (option == null) {
+    return null;
+  }
+  if (typeof option === 'string') {
+    const label = option.trim();
+    return label ? { id: label, label, original: option } : null;
+  }
+  const label = typeof option.label === 'string'
+    ? option.label.trim()
+    : typeof option.name === 'string'
+      ? option.name.trim()
+      : '';
+  if (!label) {
+    return null;
+  }
+  return {
+    id: option.id ?? label,
+    label,
+    original: option,
+  };
+};
+
 export const TagSection = ({
   tags = [],
   onRemove,
@@ -63,10 +86,71 @@ export const TagSection = ({
     [onAdd],
   );
 
-  const normalizedOptions = useMemo(() => normalizeOptions(datalistOptions), [datalistOptions]);
+  const normalizedOptions = useMemo(
+    () =>
+      normalizeOptions(datalistOptions)
+        .map((option) => normalizeQuickAddOption(option))
+        .filter(Boolean),
+    [datalistOptions],
+  );
   const containerClass = className ? `tag-list ${className}` : 'tag-list';
   const showQuickAdd = Boolean(onAdd);
 
+  const assignmentItems = useMemo(() => {
+    const map = new Map();
+
+    normalizedOptions.forEach((option) => {
+      const label = option?.label?.trim();
+      if (!label) {
+        return;
+      }
+      const key = label.toLowerCase();
+      if (map.has(key)) {
+        return;
+      }
+      map.set(key, {
+        id: option.id ?? label,
+        label,
+        state: 'none',
+        payload: option.original ?? { label },
+      });
+    });
+
+    tags.forEach((tag) => {
+      const label = typeof tag?.label === 'string' ? tag.label.trim() : '';
+      if (!label) {
+        return;
+      }
+      const key = label.toLowerCase();
+      const payload = { id: tag.id, label, color: tag.color ?? null };
+      if (map.has(key)) {
+        const entry = map.get(key);
+        entry.state = 'all';
+        entry.payload = payload;
+        return;
+      }
+      map.set(key, {
+        id: tag.id ?? label,
+        label,
+        state: 'all',
+        payload,
+      });
+    });
+
+    return Array.from(map.values());
+  }, [normalizedOptions, tags]);
+
+  const handleAssignmentSelect = useCallback(
+    (item) => {
+      if (!item) {
+        return;
+      }
+      const payload = item.payload ?? { label: item.label };
+      handleSelect(payload);
+    },
+    [handleSelect],
+  );
+
   return (
     <div className={containerClass}>
       {tags.map((tag) => {
@@ -89,14 +173,17 @@ export const TagSection = ({
         );
       })}
       {showQuickAdd ? (
-        <QuickAddMenu
-          options={normalizedOptions}
-          onCreate={handleCreate}
-          onSelectOption={(original, normalized) => handleSelect(normalized || original)}
+        <SelectionAssignmentMenu
+          label="Add tag"
+          items={assignmentItems}
           placeholder={addPlaceholder}
+          emptyMessage="No tags"
           createLabel={addButtonLabel}
-          triggerAriaLabel="Add tag"
-          triggerTitle={addButtonLabel}
+          onToggle={handleAssignmentSelect}
+          onCreate={handleCreate}
+          showStateIndicators
+          showCounts={false}
+          positionStrategy="fixed"
           triggerClassName="quick-add__chip quick-add__trigger"
           triggerContent={(
             <span className="quick-add__chip-label">
@@ -125,31 +212,82 @@ export const CorrespondentSection = ({
     [onAdd],
   );
 
-  const handleSelect = useCallback(
-    (original, normalized) => {
-      if (!onAdd) return;
-      const source = normalized && typeof normalized === 'object' ? normalized : original;
+  const normalizedOptions = useMemo(
+    () =>
+      normalizeOptions(datalistOptions)
+        .map((option) => normalizeQuickAddOption(option))
+        .filter(Boolean),
+    [datalistOptions],
+  );
+  const hasEntries = entries && entries.length > 0;
+  const showQuickAdd = Boolean(onAdd);
+  const containerClass = className ? `correspondent-list ${className}` : 'correspondent-list';
+
+  const assignmentItems = useMemo(() => {
+    const map = new Map();
+
+    normalizedOptions.forEach((option) => {
+      const label = option?.label?.trim();
+      if (!label) {
+        return;
+      }
+      const key = label.toLowerCase();
+      if (map.has(key)) {
+        return;
+      }
+      map.set(key, {
+        id: option.id ?? label,
+        label,
+        state: 'none',
+        payload: option.original ?? { name: label },
+      });
+    });
+
+    entries.forEach((entry) => {
+      const label = typeof entry?.name === 'string' ? entry.name.trim() : '';
+      if (!label) {
+        return;
+      }
+      const key = label.toLowerCase();
+      const payload = { id: entry.id, name: label };
+      if (map.has(key)) {
+        const item = map.get(key);
+        item.state = 'all';
+        item.payload = payload;
+        return;
+      }
+      map.set(key, {
+        id: entry.id ?? label,
+        label,
+        state: 'all',
+        payload,
+      });
+    });
+
+    return Array.from(map.values());
+  }, [normalizedOptions, entries]);
+
+  const handleAssignmentSelect = useCallback(
+    (item) => {
+      if (!onAdd || !item) {
+        return;
+      }
+      const source = item.payload ?? item;
       const resolvedName =
-        (source && typeof source.name === 'string' && source.name.trim()) ||
-        (typeof source === 'string' ? source.trim() : '') ||
-        (source && typeof source.label === 'string' ? source.label.trim() : '');
+        (source && typeof source.name === 'string' && source.name.trim())
+        || (typeof source === 'string' ? source.trim() : '')
+        || (source && typeof source.label === 'string' ? source.label.trim() : '');
       if (!resolvedName) {
         return;
       }
-      const payload =
-        source && typeof source === 'object'
-          ? { ...source, name: resolvedName }
-          : { id: null, name: resolvedName };
+      const payload = typeof source === 'object'
+        ? { ...source, name: resolvedName }
+        : { id: null, name: resolvedName };
       onAdd({ name: resolvedName, option: payload, input: null });
     },
     [onAdd],
   );
 
-  const normalizedOptions = useMemo(() => normalizeOptions(datalistOptions), [datalistOptions]);
-  const hasEntries = entries && entries.length > 0;
-  const showQuickAdd = Boolean(onAdd);
-  const containerClass = className ? `correspondent-list ${className}` : 'correspondent-list';
-
   return (
     <div className={containerClass}>
       {hasEntries
@@ -176,14 +314,17 @@ export const CorrespondentSection = ({
           })
         : !showQuickAdd && <span className="meta">No correspondents yet.</span>}
       {showQuickAdd ? (
-        <QuickAddMenu
-          options={normalizedOptions}
-          onCreate={handleCreate}
-          onSelectOption={(original, normalized) => handleSelect(original, normalized)}
+        <SelectionAssignmentMenu
+          label="Add correspondent"
+          items={assignmentItems}
           placeholder={addPlaceholder}
+          emptyMessage="No correspondents"
           createLabel={addButtonLabel}
-          triggerAriaLabel="Add correspondent"
-          triggerTitle={addButtonLabel}
+          onToggle={handleAssignmentSelect}
+          onCreate={handleCreate}
+          showStateIndicators
+          showCounts={false}
+          positionStrategy="fixed"
           triggerClassName="quick-add__chip quick-add__trigger"
           triggerContent={(
             <span className="quick-add__chip-label">
diff --git a/frontend/src/documents/SelectionAssignmentMenu.jsx b/frontend/src/documents/SelectionAssignmentMenu.jsx
index e5ff17b..ca75ed8 100644
--- a/frontend/src/documents/SelectionAssignmentMenu.jsx
+++ b/frontend/src/documents/SelectionAssignmentMenu.jsx
@@ -1,10 +1,6 @@
 import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react';
 import useFloatingMenu from '../ui/useFloatingMenu';
-import {
-  PlusIcon,
-  CheckIcon,
-  CircleDashedCheckIcon,
-} from '../ui/icons';
+import { CheckIcon, CircleDashedCheckIcon, PlusIcon } from '../ui/icons';
 
 const STATE_ORDER = {
   all: 0,
@@ -35,10 +31,12 @@ const SelectionAssignmentMenu = ({
   disabled = false,
   className,
   triggerContent = null,
+  triggerClassName = 'quick-add__chip quick-add__trigger panel-floating-actions__trigger',
   showStateIndicators = true,
   showCounts = true,
   onOpenMenu = null,
   renderItemLabel = null,
+  positionStrategy = 'absolute',
 }) => {
   const anchorRef = useRef(null);
   const inputRef = useRef(null);
@@ -55,7 +53,7 @@ const SelectionAssignmentMenu = ({
   } = useFloatingMenu({
     anchorRef,
     align: 'center',
-    positionStrategy: 'absolute',
+    positionStrategy,
     minWidth: 220,
   });
 
@@ -117,7 +115,8 @@ const SelectionAssignmentMenu = ({
   );
 
   const handleCreate = useCallback(
-    async () => {
+    async (event) => {
+      event?.preventDefault?.();
       if (typeof onCreate !== 'function') {
         return;
       }
@@ -144,9 +143,12 @@ const SelectionAssignmentMenu = ({
   );
 
   const canCreate = Boolean(onCreate);
-  const showCreateOption = canCreate
-    && query.trim().length > 0
-    && !existingLabels.has(query.trim().toLowerCase());
+  const trimmedQuery = query.trim();
+  const queryKey = trimmedQuery.toLowerCase();
+  const canSubmitCreate = canCreate
+    && trimmedQuery.length > 0
+    && !existingLabels.has(queryKey)
+    && !pending;
 
   const handleTriggerClick = useCallback(() => {
     if (disabled) {
@@ -163,7 +165,7 @@ const SelectionAssignmentMenu = ({
       <button
         type="button"
         ref={anchorRef}
-        className="quick-add__chip quick-add__trigger panel-floating-actions__trigger"
+        className={triggerClassName}
         onClick={handleTriggerClick}
         aria-haspopup="menu"
         aria-expanded={isOpen}
@@ -184,15 +186,28 @@ const SelectionAssignmentMenu = ({
           data-floating-position
         >
           <div className="selection-assignment__header">
-            <input
-              ref={inputRef}
-              type="text"
-              value={query}
-              onChange={(event) => setQuery(event.target.value)}
-              placeholder={placeholder}
-              aria-label={placeholder}
-              disabled={pending}
-            />
+            <form className="selection-assignment__form" onSubmit={handleCreate}>
+              <input
+                ref={inputRef}
+                type="text"
+                value={query}
+                onChange={(event) => setQuery(event.target.value)}
+                placeholder={placeholder}
+                aria-label={placeholder}
+                disabled={pending}
+              />
+              {canCreate ? (
+                <button
+                  type="submit"
+                  className="icon-button selection-assignment__add"
+                  disabled={!canSubmitCreate}
+                  aria-label={createLabel || 'Add'}
+                  title={createLabel || 'Add'}
+                >
+                  <PlusIcon aria-hidden="true" />
+                </button>
+              ) : null}
+            </form>
           </div>
           <div className="selection-assignment__list" role="presentation">
             {filteredItems.length ? (
@@ -237,19 +252,6 @@ const SelectionAssignmentMenu = ({
               <div className="menu__empty selection-assignment__empty">{emptyMessage}</div>
             )}
           </div>
-          {showCreateOption ? (
-            <button
-              type="button"
-              className="menu__item selection-assignment__create"
-              onClick={handleCreate}
-              disabled={pending}
-            >
-              <PlusIcon className="selection-assignment__icon" aria-hidden="true" />
-              <span className="selection-assignment__label">
-                {createLabel ? `${createLabel} “${query.trim()}”` : `Create “${query.trim()}”`}
-              </span>
-            </button>
-          ) : null}
         </div>
       ) : null}
     </div>
diff --git a/frontend/src/documents/panel/createDocumentsSurface.js b/frontend/src/documents/panel/createDocumentsSurface.js
index 794e2f4..a0ee776 100644
--- a/frontend/src/documents/panel/createDocumentsSurface.js
+++ b/frontend/src/documents/panel/createDocumentsSurface.js
@@ -93,12 +93,13 @@ const createDocumentsSurface = ({
   const sidebarToggle = renderSidebarToggle ? renderSidebarToggle() : null;
   const detail = detailOpen && detailProps
     ? (() => {
-        const { onClose, onOpenPreview, ...restDetailProps } = detailProps;
+        const { onClose, onOpenPreview, tags: tagOptions, ...restDetailProps } = detailProps;
         return (
           <DocumentViewerPanel
             variant="sidebar"
             onCollapsePanel={onClose}
             onMaximizePanel={onOpenPreview}
+            tagOptions={tagOptions}
             {...restDetailProps}
           />
         );
diff --git a/frontend/src/styles/detail/detail-panels.css b/frontend/src/styles/detail/detail-panels.css
index c30b43a..f5584c6 100644
--- a/frontend/src/styles/detail/detail-panels.css
+++ b/frontend/src/styles/detail/detail-panels.css
@@ -74,10 +74,6 @@
   flex: 1;
 }
 
-.detail-panel__content .document-viewer-panel__body {
-  padding: 0.5rem 0.5rem 0;
-}
-
 .detail-section__header {
   display: flex;
   align-items: center;
@@ -195,7 +191,14 @@
   border-bottom: 1px solid var(--border-subtle);
 }
 
-.selection-assignment__header input {
+.selection-assignment__form {
+  display: flex;
+  gap: 0.4rem;
+  align-items: stretch;
+}
+
+.selection-assignment__form input {
+  flex: 1 1 auto;
   width: 100%;
   padding: 0.35rem 0.6rem;
   border: 1px solid var(--border-subtle);
@@ -205,12 +208,20 @@
   font-size: 0.95rem;
 }
 
-.selection-assignment__header input:focus-visible {
+.selection-assignment__form input:focus-visible {
   outline: none;
   border-color: color-mix(in oklch, var(--accent) 60%, transparent);
   box-shadow: 0 0 0 1px color-mix(in oklch, var(--accent) 35%, transparent);
 }
 
+.selection-assignment__add {
+  align-self: stretch;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  min-width: 2rem;
+}
+
 .selection-assignment__list {
   max-height: max(240px, 50vh);
   overflow-y: auto;
diff --git a/frontend/src/styles/sidebar/sidebar.css b/frontend/src/styles/sidebar/sidebar.css
index a1a8479..2fcba18 100644
--- a/frontend/src/styles/sidebar/sidebar.css
+++ b/frontend/src/styles/sidebar/sidebar.css
@@ -236,7 +236,7 @@
   box-shadow: 0 12px 28px var(--shadow-strong);
   min-width: 220px;
   z-index: 2500000;
-  overflow: hidden;
+  overflow: visible;
 }
 
 .menu[data-floating-position] {
@@ -247,6 +247,7 @@
 
 .menu__list {
   overflow-y: auto;
+  max-height: min(20rem, 60vh);
   padding: 0.25rem;
   display: flex;
   flex-direction: column;