diff --git a/ui/src/views/Forecast.jsx b/ui/src/views/Forecast.jsx
index affd063..fe05b10 100644
--- a/ui/src/views/Forecast.jsx
+++ b/ui/src/views/Forecast.jsx
@@ -1,5 +1,6 @@
 import { useState, useEffect, useRef } from 'react'
 import useTheme from '../theme.jsx'
+import useAuth from '../auth.jsx'
 import OperationPanel from '../components/OperationPanel.jsx'
 import BridgeView from '../components/BridgeView.jsx'
 
@@ -54,6 +55,11 @@ const DEAD_ORDER_EXPRS = ['pf_bucket_ord', 'pf_segment_ord', 'Bucket', 'Segment'
 
 export default function Forecast({ sources = [], sourceId, versions = [], versionId, refreshSources }) {
   const { dark } = useTheme()
+  const { user } = useAuth()
+  // Undo removes an entry's rows wholesale, so the server allows it only to the
+  // account that made it, or an admin. Mirrored here to say so before the click
+  // rather than after the 403.
+  const canUndo = (entry) => !!user && (user.is_admin || entry.pf_user === user.username)
   const [loading,      setLoading]      = useState(false)
   const [largeDataset, setLargeDataset] = useState(false)
   // The pivot's own filter, refreshed whenever the ledger recomputes. A ref
@@ -1902,6 +1908,7 @@ export default function Forecast({ sources = [], sourceId, versions = [], versio
                       <th className="text-left px-3 py-2 font-medium">Slice</th>
                       <th className="text-left px-3 py-2 font-medium w-32">Tag</th>
                       <th className="text-left px-3 py-2 font-medium w-48">Note</th>
+                      <th className="text-left px-3 py-2 font-medium w-24">By</th>
                       <th className="text-right px-3 py-2 font-medium w-28">Value</th>
                       <th className="text-right px-3 py-2 font-medium w-16">Rows</th>
                       <th className="px-3 py-2 w-16"></th>
@@ -1935,6 +1942,9 @@ export default function Forecast({ sources = [], sourceId, versions = [], versio
                           )} />
                         <LogCell entry={entry} field="note" placeholder="add note"
                           editing={editingCell} setEditing={setEditingCell} onSave={saveLogField} />
+                        <td className="px-3 py-2 text-gray-500 truncate" title={entry.pf_user || ''}>
+                          {entry.pf_user || '—'}
+                        </td>
                         <td className={`px-3 py-2 text-right tabular-nums whitespace-nowrap ${
                           entry.value_total > 0 ? 'text-green-700' : entry.value_total < 0 ? 'text-red-600' : 'text-gray-400'}`}>
                           {entry.value_total == null ? '—'
@@ -1944,8 +1954,15 @@ export default function Forecast({ sources = [], sourceId, versions = [], versio
                         <td className="px-3 py-2">
                           <button
                             onClick={() => undoEntry(entry.id)}
-                            disabled={undoingId === entry.id}
-                            className="text-xs border border-red-200 text-red-400 hover:text-red-600 hover:border-red-400 rounded px-2 py-0.5 disabled:opacity-40 whitespace-nowrap">
+                            disabled={undoingId === entry.id || !canUndo(entry)}
+                            title={canUndo(entry)
+                              ? 'Remove this entry and its rows'
+                              : `Only ${entry.pf_user || 'the author'} or an administrator can undo this`}
+                            className={`text-xs rounded px-2 py-0.5 whitespace-nowrap border ${
+                              canUndo(entry)
+                                ? 'border-red-200 text-red-400 hover:text-red-600 hover:border-red-400'
+                                : 'border-gray-100 text-gray-300 cursor-not-allowed'
+                            } disabled:opacity-100`}>
                             {undoingId === entry.id ? '…' : 'Undo'}
                           </button>
                         </td>
@@ -1955,7 +1972,7 @@ export default function Forecast({ sources = [], sourceId, versions = [], versio
                       if (expandedLog !== entry.id) return [row]
                       return [row, (
                         <tr key={`${entry.id}-detail`} className="bg-gray-50 border-t border-gray-100">
-                          <td colSpan={8} className="px-3 py-3">
+                          <td colSpan={9} className="px-3 py-3">
                             <div className="grid gap-3 md:grid-cols-2">
                               <LogJson label="slice"  value={entry.slice} />
                               <LogJson label="params" value={entry.params} />