diff --git a/client/src/api/client.ts b/client/src/api/client.ts
index 7e8f28b..6726140 100644
--- a/client/src/api/client.ts
+++ b/client/src/api/client.ts
@@ -197,6 +197,9 @@ export const filesApi = {
   restore: (tripId: number | string, id: number) => apiClient.post(`/trips/${tripId}/files/${id}/restore`).then(r => r.data),
   permanentDelete: (tripId: number | string, id: number) => apiClient.delete(`/trips/${tripId}/files/${id}/permanent`).then(r => r.data),
   emptyTrash: (tripId: number | string) => apiClient.delete(`/trips/${tripId}/files/trash/empty`).then(r => r.data),
+  addLink: (tripId: number | string, fileId: number, data: { reservation_id?: number; assignment_id?: number }) => apiClient.post(`/trips/${tripId}/files/${fileId}/link`, data).then(r => r.data),
+  removeLink: (tripId: number | string, fileId: number, linkId: number) => apiClient.delete(`/trips/${tripId}/files/${fileId}/link/${linkId}`).then(r => r.data),
+  getLinks: (tripId: number | string, fileId: number) => apiClient.get(`/trips/${tripId}/files/${fileId}/links`).then(r => r.data),
 }
 
 export const reservationsApi = {
diff --git a/client/src/components/Files/FileManager.tsx b/client/src/components/Files/FileManager.tsx
index c5fc0bd..2f62c1b 100644
--- a/client/src/components/Files/FileManager.tsx
+++ b/client/src/components/Files/FileManager.tsx
@@ -302,10 +302,15 @@ export default function FileManager({ files = [], onUpload, onDelete, onUpdate,
 
   const renderFileRow = (file: TripFile, isTrash = false) => {
     const FileIcon = getFileIcon(file.mime_type)
-    const linkedPlace = places?.find(p => p.id === file.place_id)
-    const linkedReservation = file.reservation_id
-      ? (reservations?.find(r => r.id === file.reservation_id) || { title: file.reservation_title })
-      : null
+    const allLinkedPlaceIds = new Set<number>()
+    if (file.place_id) allLinkedPlaceIds.add(file.place_id)
+    for (const pid of (file.linked_place_ids || [])) allLinkedPlaceIds.add(pid)
+    const linkedPlaces = [...allLinkedPlaceIds].map(pid => places?.find(p => p.id === pid)).filter(Boolean)
+    // All linked reservations (primary + file_links)
+    const allLinkedResIds = new Set<number>()
+    if (file.reservation_id) allLinkedResIds.add(file.reservation_id)
+    for (const rid of (file.linked_reservation_ids || [])) allLinkedResIds.add(rid)
+    const linkedReservations = [...allLinkedResIds].map(rid => reservations?.find(r => r.id === rid)).filter(Boolean)
     const fileUrl = file.url || (file.filename?.startsWith('files/') ? `/uploads/${file.filename}` : `/uploads/files/${file.filename}`)
 
     return (
@@ -365,12 +370,12 @@ export default function FileManager({ files = [], onUpload, onDelete, onUpdate,
             {file.file_size && <span style={{ fontSize: 11, color: 'var(--text-faint)' }}>{formatSize(file.file_size)}</span>}
             <span style={{ fontSize: 11, color: 'var(--text-faint)' }}>{formatDateWithLocale(file.created_at, locale)}</span>
 
-            {linkedPlace && (
-              <SourceBadge icon={MapPin} label={`${t('files.sourcePlan')} · ${linkedPlace.name}`} />
-            )}
-            {linkedReservation && (
-              <SourceBadge icon={Ticket} label={`${t('files.sourceBooking')} · ${linkedReservation.title || t('files.sourceBooking')}`} />
-            )}
+            {linkedPlaces.map(p => (
+              <SourceBadge key={p.id} icon={MapPin} label={`${t('files.sourcePlan')} · ${p.name}`} />
+            ))}
+            {linkedReservations.map(r => (
+              <SourceBadge key={r.id} icon={Ticket} label={`${t('files.sourceBooking')} · ${r.title || t('files.sourceBooking')}`} />
+            ))}
             {file.note_id && (
               <SourceBadge icon={StickyNote} label={t('files.sourceCollab') || 'Collab Notes'} />
             )}
@@ -477,20 +482,45 @@ export default function FileManager({ files = [], onUpload, onDelete, onUpdate,
                   }
                 }
                 const unassigned = places.filter(p => !assignedPlaceIds.has(p.id))
-                const placeBtn = (p: Place) => (
-                  <button key={p.id} onClick={() => handleAssign(file.id, { place_id: file.place_id === p.id ? null : p.id })} style={{
-                    width: '100%', textAlign: 'left', padding: '6px 10px 6px 20px', background: file.place_id === p.id ? 'var(--bg-hover)' : 'none',
-                    border: 'none', cursor: 'pointer', fontSize: 13, color: 'var(--text-primary)',
-                    borderRadius: 8, fontFamily: 'inherit', fontWeight: file.place_id === p.id ? 600 : 400,
-                    display: 'flex', alignItems: 'center', gap: 6,
-                  }}
-                    onMouseEnter={e => e.currentTarget.style.background = 'var(--bg-hover)'}
-                    onMouseLeave={e => e.currentTarget.style.background = file.place_id === p.id ? 'var(--bg-hover)' : 'transparent'}>
-                    <MapPin size={12} style={{ flexShrink: 0, color: 'var(--text-muted)' }} />
-                    <span style={{ overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>{p.name}</span>
-                    {file.place_id === p.id && <Check size={14} style={{ marginLeft: 'auto', flexShrink: 0, color: 'var(--accent)' }} />}
-                  </button>
-                )
+                const placeBtn = (p: Place) => {
+                  const isLinked = file.place_id === p.id || (file.linked_place_ids || []).includes(p.id)
+                  return (
+                    <button key={p.id} onClick={async () => {
+                      if (isLinked) {
+                        if (file.place_id === p.id) {
+                          await handleAssign(file.id, { place_id: null })
+                        } else {
+                          try {
+                            const linksRes = await filesApi.getLinks(tripId, file.id)
+                            const link = (linksRes.links || []).find((l: any) => l.place_id === p.id)
+                            if (link) await filesApi.removeLink(tripId, file.id, link.id)
+                            refreshFiles()
+                          } catch {}
+                        }
+                      } else {
+                        if (!file.place_id) {
+                          await handleAssign(file.id, { place_id: p.id })
+                        } else {
+                          try {
+                            await filesApi.addLink(tripId, file.id, { place_id: p.id })
+                            refreshFiles()
+                          } catch {}
+                        }
+                      }
+                    }} style={{
+                      width: '100%', textAlign: 'left', padding: '6px 10px 6px 20px', background: isLinked ? 'var(--bg-hover)' : 'none',
+                      border: 'none', cursor: 'pointer', fontSize: 13, color: 'var(--text-primary)',
+                      borderRadius: 8, fontFamily: 'inherit', fontWeight: isLinked ? 600 : 400,
+                      display: 'flex', alignItems: 'center', gap: 6,
+                    }}
+                      onMouseEnter={e => e.currentTarget.style.background = 'var(--bg-hover)'}
+                      onMouseLeave={e => e.currentTarget.style.background = isLinked ? 'var(--bg-hover)' : 'transparent'}>
+                      <MapPin size={12} style={{ flexShrink: 0, color: 'var(--text-muted)' }} />
+                      <span style={{ overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>{p.name}</span>
+                      {isLinked && <Check size={14} style={{ marginLeft: 'auto', flexShrink: 0, color: 'var(--accent)' }} />}
+                    </button>
+                  )
+                }
 
                 const placesSection = places.length > 0 && (
                   <div style={{ flex: 1, minWidth: 0 }}>
@@ -519,20 +549,47 @@ export default function FileManager({ files = [], onUpload, onDelete, onUpdate,
                     <div style={{ fontSize: 11, fontWeight: 600, color: 'var(--text-faint)', padding: '8px 10px 4px', textTransform: 'uppercase', letterSpacing: 0.5 }}>
                       {t('files.assignBooking')}
                     </div>
-                    {reservations.map(r => (
-                      <button key={r.id} onClick={() => handleAssign(file.id, { reservation_id: file.reservation_id === r.id ? null : r.id })} style={{
-                        width: '100%', textAlign: 'left', padding: '6px 10px 6px 20px', background: file.reservation_id === r.id ? 'var(--bg-hover)' : 'none',
-                        border: 'none', cursor: 'pointer', fontSize: 13, color: 'var(--text-primary)',
-                        borderRadius: 8, fontFamily: 'inherit', fontWeight: file.reservation_id === r.id ? 600 : 400,
-                        display: 'flex', alignItems: 'center', gap: 6,
-                      }}
-                        onMouseEnter={e => e.currentTarget.style.background = 'var(--bg-hover)'}
-                        onMouseLeave={e => e.currentTarget.style.background = file.reservation_id === r.id ? 'var(--bg-hover)' : 'transparent'}>
-                        <Ticket size={12} style={{ flexShrink: 0, color: 'var(--text-muted)' }} />
-                        <span style={{ overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>{r.title || r.name}</span>
-                        {file.reservation_id === r.id && <Check size={14} style={{ marginLeft: 'auto', flexShrink: 0, color: 'var(--accent)' }} />}
-                      </button>
-                    ))}
+                    {reservations.map(r => {
+                      const isLinked = file.reservation_id === r.id || (file.linked_reservation_ids || []).includes(r.id)
+                      return (
+                        <button key={r.id} onClick={async () => {
+                          if (isLinked) {
+                            // Unlink: if primary reservation_id, clear it; if via file_links, remove link
+                            if (file.reservation_id === r.id) {
+                              await handleAssign(file.id, { reservation_id: null })
+                            } else {
+                              try {
+                                const linksRes = await filesApi.getLinks(tripId, file.id)
+                                const link = (linksRes.links || []).find((l: any) => l.reservation_id === r.id)
+                                if (link) await filesApi.removeLink(tripId, file.id, link.id)
+                                refreshFiles()
+                              } catch {}
+                            }
+                          } else {
+                            // Link: if no primary, set it; otherwise use file_links
+                            if (!file.reservation_id) {
+                              await handleAssign(file.id, { reservation_id: r.id })
+                            } else {
+                              try {
+                                await filesApi.addLink(tripId, file.id, { reservation_id: r.id })
+                                refreshFiles()
+                              } catch {}
+                            }
+                          }
+                        }} style={{
+                          width: '100%', textAlign: 'left', padding: '6px 10px 6px 20px', background: isLinked ? 'var(--bg-hover)' : 'none',
+                          border: 'none', cursor: 'pointer', fontSize: 13, color: 'var(--text-primary)',
+                          borderRadius: 8, fontFamily: 'inherit', fontWeight: isLinked ? 600 : 400,
+                          display: 'flex', alignItems: 'center', gap: 6,
+                        }}
+                          onMouseEnter={e => e.currentTarget.style.background = 'var(--bg-hover)'}
+                          onMouseLeave={e => e.currentTarget.style.background = isLinked ? 'var(--bg-hover)' : 'transparent'}>
+                          <Ticket size={12} style={{ flexShrink: 0, color: 'var(--text-muted)' }} />
+                          <span style={{ overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>{r.title || r.name}</span>
+                          {isLinked && <Check size={14} style={{ marginLeft: 'auto', flexShrink: 0, color: 'var(--accent)' }} />}
+                        </button>
+                      )
+                    })}
                   </div>
                 )
 
diff --git a/client/src/components/Planner/PlaceInspector.tsx b/client/src/components/Planner/PlaceInspector.tsx
index a6b993e..7d46a7c 100644
--- a/client/src/components/Planner/PlaceInspector.tsx
+++ b/client/src/components/Planner/PlaceInspector.tsx
@@ -169,7 +169,7 @@ export default function PlaceInspector({
   const selectedDay = days?.find(d => d.id === selectedDayId)
   const weekdayIndex = getWeekdayIndex(selectedDay?.date)
 
-  const placeFiles = (files || []).filter(f => String(f.place_id) === String(place.id))
+  const placeFiles = (files || []).filter(f => String(f.place_id) === String(place.id) || (f.linked_place_ids || []).includes(place.id))
 
   const handleFileUpload = useCallback(async (e) => {
     const selectedFiles = Array.from((e.target as HTMLInputElement).files || [])
diff --git a/client/src/components/Planner/ReservationModal.tsx b/client/src/components/Planner/ReservationModal.tsx
index dafaac4..85d9e88 100644
--- a/client/src/components/Planner/ReservationModal.tsx
+++ b/client/src/components/Planner/ReservationModal.tsx
@@ -1,4 +1,7 @@
 import { useState, useEffect, useRef, useMemo } from 'react'
+import { useParams } from 'react-router-dom'
+import apiClient from '../../api/client'
+import { useTripStore } from '../../store/tripStore'
 import Modal from '../shared/Modal'
 import CustomSelect from '../shared/CustomSelect'
 import { Plane, Hotel, Utensils, Train, Car, Ship, Ticket, FileText, Users, Paperclip, X, ExternalLink, Link2 } from 'lucide-react'
@@ -62,6 +65,8 @@ interface ReservationModalProps {
 }
 
 export function ReservationModal({ isOpen, onClose, onSave, reservation, days, places, assignments, selectedDayId, files = [], onFileUpload, onFileDelete, accommodations = [] }: ReservationModalProps) {
+  const { id: tripId } = useParams<{ id: string }>()
+  const loadFiles = useTripStore(s => s.loadFiles)
   const toast = useToast()
   const { t, locale } = useTranslation()
   const fileInputRef = useRef(null)
@@ -78,6 +83,9 @@ export function ReservationModal({ isOpen, onClose, onSave, reservation, days, p
   const [isSaving, setIsSaving] = useState(false)
   const [uploadingFile, setUploadingFile] = useState(false)
   const [pendingFiles, setPendingFiles] = useState([])
+  const [showFilePicker, setShowFilePicker] = useState(false)
+  const [linkedFileIds, setLinkedFileIds] = useState<number[]>([])
+  const [unlinkedFileIds, setUnlinkedFileIds] = useState<number[]>([])
 
   const assignmentOptions = useMemo(
     () => buildAssignmentOptions(days, assignments, t, locale),
@@ -204,7 +212,13 @@ export function ReservationModal({ isOpen, onClose, onSave, reservation, days, p
     }
   }
 
-  const attachedFiles = reservation?.id ? files.filter(f => f.reservation_id === reservation.id) : []
+  const attachedFiles = reservation?.id
+    ? files.filter(f =>
+        f.reservation_id === reservation.id ||
+        linkedFileIds.includes(f.id) ||
+        (f.linked_reservation_ids && f.linked_reservation_ids.includes(reservation.id))
+      )
+    : []
 
   const inputStyle = {
     width: '100%', border: '1px solid var(--border-primary)', borderRadius: 10,
@@ -459,11 +473,23 @@ export function ReservationModal({ isOpen, onClose, onSave, reservation, days, p
                 <FileText size={12} style={{ color: 'var(--text-muted)', flexShrink: 0 }} />
                 <span style={{ flex: 1, fontSize: 12, color: 'var(--text-secondary)', overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>{f.original_name}</span>
                 <a href={f.url} target="_blank" rel="noreferrer" style={{ color: 'var(--text-faint)', display: 'flex', flexShrink: 0 }}><ExternalLink size={11} /></a>
-                {onFileDelete && (
-                  <button type="button" onClick={() => onFileDelete(f.id)} style={{ background: 'none', border: 'none', cursor: 'pointer', color: 'var(--text-faint)', display: 'flex', padding: 0, flexShrink: 0 }}>
-                    <X size={11} />
-                  </button>
-                )}
+                <button type="button" onClick={async () => {
+                  // Always unlink, never delete the file
+                  // Clear primary reservation_id if it points to this reservation
+                  if (f.reservation_id === reservation?.id) {
+                    try { await apiClient.put(`/trips/${tripId}/files/${f.id}`, { reservation_id: null }) } catch {}
+                  }
+                  // Remove from file_links if linked there
+                  try {
+                    const linksRes = await apiClient.get(`/trips/${tripId}/files/${f.id}/links`)
+                    const link = (linksRes.data.links || []).find((l: any) => l.reservation_id === reservation?.id)
+                    if (link) await apiClient.delete(`/trips/${tripId}/files/${f.id}/link/${link.id}`)
+                  } catch {}
+                  setLinkedFileIds(prev => prev.filter(id => id !== f.id))
+                  if (tripId) loadFiles(tripId)
+                }} style={{ background: 'none', border: 'none', cursor: 'pointer', color: 'var(--text-faint)', display: 'flex', padding: 0, flexShrink: 0 }}>
+                  <X size={11} />
+                </button>
               </div>
             ))}
             {pendingFiles.map((f, i) => (
@@ -477,14 +503,56 @@ export function ReservationModal({ isOpen, onClose, onSave, reservation, days, p
               </div>
             ))}
             <input ref={fileInputRef} type="file" accept=".pdf,.doc,.docx,.txt,image/*" style={{ display: 'none' }} onChange={handleFileChange} />
-            <button type="button" onClick={() => fileInputRef.current?.click()} disabled={uploadingFile} style={{
-              display: 'flex', alignItems: 'center', gap: 5, padding: '6px 10px',
-              border: '1px dashed var(--border-primary)', borderRadius: 8, background: 'none',
-              fontSize: 11, color: 'var(--text-faint)', cursor: uploadingFile ? 'default' : 'pointer', fontFamily: 'inherit',
-            }}>
-              <Paperclip size={11} />
-              {uploadingFile ? t('reservations.uploading') : t('reservations.attachFile')}
-            </button>
+            <div style={{ display: 'flex', gap: 6, flexWrap: 'wrap' }}>
+              <button type="button" onClick={() => fileInputRef.current?.click()} disabled={uploadingFile} style={{
+                display: 'flex', alignItems: 'center', gap: 5, padding: '6px 10px',
+                border: '1px dashed var(--border-primary)', borderRadius: 8, background: 'none',
+                fontSize: 11, color: 'var(--text-faint)', cursor: uploadingFile ? 'default' : 'pointer', fontFamily: 'inherit',
+              }}>
+                <Paperclip size={11} />
+                {uploadingFile ? t('reservations.uploading') : t('reservations.attachFile')}
+              </button>
+              {/* Link existing file picker */}
+              {reservation?.id && files.filter(f => !f.deleted_at && !attachedFiles.some(af => af.id === f.id)).length > 0 && (
+                <div style={{ position: 'relative' }}>
+                  <button type="button" onClick={() => setShowFilePicker(v => !v)} style={{
+                    display: 'flex', alignItems: 'center', gap: 5, padding: '6px 10px',
+                    border: '1px dashed var(--border-primary)', borderRadius: 8, background: 'none',
+                    fontSize: 11, color: 'var(--text-faint)', cursor: 'pointer', fontFamily: 'inherit',
+                  }}>
+                    <Link2 size={11} /> {t('reservations.linkExisting')}
+                  </button>
+                  {showFilePicker && (
+                    <div style={{
+                      position: 'absolute', bottom: '100%', left: 0, marginBottom: 4, zIndex: 50,
+                      background: 'var(--bg-card)', border: '1px solid var(--border-primary)', borderRadius: 10,
+                      boxShadow: '0 4px 16px rgba(0,0,0,0.12)', padding: 4, minWidth: 220, maxHeight: 200, overflowY: 'auto',
+                    }}>
+                      {files.filter(f => !f.deleted_at && !attachedFiles.some(af => af.id === f.id)).map(f => (
+                        <button key={f.id} type="button" onClick={async () => {
+                          try {
+                            await apiClient.post(`/trips/${tripId}/files/${f.id}/link`, { reservation_id: reservation.id })
+                            setLinkedFileIds(prev => [...prev, f.id])
+                            setShowFilePicker(false)
+                            if (tripId) loadFiles(tripId)
+                          } catch {}
+                        }}
+                          style={{
+                            display: 'flex', alignItems: 'center', gap: 8, width: '100%', padding: '6px 10px',
+                            background: 'none', border: 'none', cursor: 'pointer', fontSize: 12, fontFamily: 'inherit',
+                            color: 'var(--text-secondary)', borderRadius: 7, textAlign: 'left',
+                          }}
+                          onMouseEnter={e => e.currentTarget.style.background = 'var(--bg-tertiary)'}
+                          onMouseLeave={e => e.currentTarget.style.background = 'none'}>
+                          <FileText size={12} style={{ color: 'var(--text-faint)', flexShrink: 0 }} />
+                          <span style={{ overflow: 'hidden', textOverflow: 'ellipsis', whiteSpace: 'nowrap' }}>{f.original_name}</span>
+                        </button>
+                      ))}
+                    </div>
+                  )}
+                </div>
+              )}
+            </div>
           </div>
         </div>
 
diff --git a/client/src/components/Planner/ReservationsPanel.tsx b/client/src/components/Planner/ReservationsPanel.tsx
index c8de359..86c844f 100644
--- a/client/src/components/Planner/ReservationsPanel.tsx
+++ b/client/src/components/Planner/ReservationsPanel.tsx
@@ -65,7 +65,7 @@ function ReservationCard({ r, tripId, onEdit, onDelete, files = [], onNavigateTo
   const typeInfo = getType(r.type)
   const TypeIcon = typeInfo.Icon
   const confirmed = r.status === 'confirmed'
-  const attachedFiles = files.filter(f => f.reservation_id === r.id)
+  const attachedFiles = files.filter(f => f.reservation_id === r.id || (f.linked_reservation_ids || []).includes(r.id))
   const linked = r.assignment_id ? assignmentLookup[r.assignment_id] : null
 
   const handleToggle = async () => {
diff --git a/client/src/i18n/translations/ar.ts b/client/src/i18n/translations/ar.ts
index c216f35..e4d5070 100644
--- a/client/src/i18n/translations/ar.ts
+++ b/client/src/i18n/translations/ar.ts
@@ -750,6 +750,7 @@ const ar: Record<string, string | { name: string; category: string }[]> = {
   'reservations.pendingSave': 'سيتم الحفظ…',
   'reservations.uploading': 'جارٍ الرفع...',
   'reservations.attachFile': 'إرفاق ملف',
+  'reservations.linkExisting': 'ربط ملف موجود',
   'reservations.toast.saveError': 'فشل الحفظ',
   'reservations.toast.updateError': 'فشل التحديث',
   'reservations.toast.deleteError': 'فشل الحذف',
diff --git a/client/src/i18n/translations/de.ts b/client/src/i18n/translations/de.ts
index fdc437d..840a4f2 100644
--- a/client/src/i18n/translations/de.ts
+++ b/client/src/i18n/translations/de.ts
@@ -758,6 +758,7 @@ const de: Record<string, string | { name: string; category: string }[]> = {
   'reservations.pendingSave': 'wird gespeichert…',
   'reservations.uploading': 'Wird hochgeladen...',
   'reservations.attachFile': 'Datei anhängen',
+  'reservations.linkExisting': 'Vorhandene verknüpfen',
   'reservations.linkAssignment': 'Mit Tagesplanung verknüpfen',
   'reservations.pickAssignment': 'Zuordnung aus dem Plan wählen...',
   'reservations.noAssignment': 'Keine Verknüpfung',
diff --git a/client/src/i18n/translations/en.ts b/client/src/i18n/translations/en.ts
index 4a89978..18d79ac 100644
--- a/client/src/i18n/translations/en.ts
+++ b/client/src/i18n/translations/en.ts
@@ -754,6 +754,7 @@ const en: Record<string, string | { name: string; category: string }[]> = {
   'reservations.pendingSave': 'will be saved…',
   'reservations.uploading': 'Uploading...',
   'reservations.attachFile': 'Attach file',
+  'reservations.linkExisting': 'Link existing file',
   'reservations.toast.saveError': 'Failed to save',
   'reservations.toast.updateError': 'Failed to update',
   'reservations.toast.deleteError': 'Failed to delete',
diff --git a/client/src/i18n/translations/es.ts b/client/src/i18n/translations/es.ts
index e8448fc..3cb293f 100644
--- a/client/src/i18n/translations/es.ts
+++ b/client/src/i18n/translations/es.ts
@@ -706,6 +706,7 @@ const es: Record<string, string> = {
   'reservations.pendingSave': 'se guardará…',
   'reservations.uploading': 'Subiendo...',
   'reservations.attachFile': 'Adjuntar archivo',
+  'reservations.linkExisting': 'Vincular archivo existente',
   'reservations.toast.saveError': 'No se pudo guardar',
   'reservations.toast.updateError': 'No se pudo actualizar',
   'reservations.toast.deleteError': 'No se pudo eliminar',
diff --git a/client/src/i18n/translations/fr.ts b/client/src/i18n/translations/fr.ts
index 51e95cd..722e8d8 100644
--- a/client/src/i18n/translations/fr.ts
+++ b/client/src/i18n/translations/fr.ts
@@ -743,6 +743,7 @@ const fr: Record<string, string> = {
   'reservations.pendingSave': 'sera enregistré…',
   'reservations.uploading': 'Téléversement...',
   'reservations.attachFile': 'Joindre un fichier',
+  'reservations.linkExisting': 'Lier un fichier existant',
   'reservations.toast.saveError': 'Échec de l\'enregistrement',
   'reservations.toast.updateError': 'Échec de la mise à jour',
   'reservations.toast.deleteError': 'Échec de la suppression',
diff --git a/client/src/i18n/translations/nl.ts b/client/src/i18n/translations/nl.ts
index 89407f7..add8dd6 100644
--- a/client/src/i18n/translations/nl.ts
+++ b/client/src/i18n/translations/nl.ts
@@ -743,6 +743,7 @@ const nl: Record<string, string> = {
   'reservations.pendingSave': 'wordt opgeslagen…',
   'reservations.uploading': 'Uploaden...',
   'reservations.attachFile': 'Bestand bijvoegen',
+  'reservations.linkExisting': 'Bestaand bestand koppelen',
   'reservations.toast.saveError': 'Opslaan mislukt',
   'reservations.toast.updateError': 'Bijwerken mislukt',
   'reservations.toast.deleteError': 'Verwijderen mislukt',
diff --git a/client/src/i18n/translations/ru.ts b/client/src/i18n/translations/ru.ts
index 75d29ba..039f8dc 100644
--- a/client/src/i18n/translations/ru.ts
+++ b/client/src/i18n/translations/ru.ts
@@ -743,6 +743,7 @@ const ru: Record<string, string> = {
   'reservations.pendingSave': 'будет сохранено…',
   'reservations.uploading': 'Загрузка...',
   'reservations.attachFile': 'Прикрепить файл',
+  'reservations.linkExisting': 'Привязать существующий файл',
   'reservations.toast.saveError': 'Ошибка сохранения',
   'reservations.toast.updateError': 'Ошибка обновления',
   'reservations.toast.deleteError': 'Ошибка удаления',
diff --git a/client/src/i18n/translations/zh.ts b/client/src/i18n/translations/zh.ts
index fbe1121..6da7988 100644
--- a/client/src/i18n/translations/zh.ts
+++ b/client/src/i18n/translations/zh.ts
@@ -743,6 +743,7 @@ const zh: Record<string, string> = {
   'reservations.pendingSave': '将被保存…',
   'reservations.uploading': '上传中...',
   'reservations.attachFile': '附加文件',
+  'reservations.linkExisting': '关联已有文件',
   'reservations.toast.saveError': '保存失败',
   'reservations.toast.updateError': '更新失败',
   'reservations.toast.deleteError': '删除失败',
diff --git a/server/src/db/migrations.ts b/server/src/db/migrations.ts
index 816288b..55078fd 100644
--- a/server/src/db/migrations.ts
+++ b/server/src/db/migrations.ts
@@ -307,6 +307,20 @@ function runMigrations(db: Database.Database): void {
         db.prepare("INSERT INTO addons (id, name, type, icon, enabled, sort_order) VALUES (?, ?, ?, ?, ?, ?)").run('memories', 'Photos', 'trip', 'Image', 0, 7);
       } catch {}
     },
+    () => {
+      // Allow files to be linked to multiple reservations/assignments
+      db.exec(`CREATE TABLE IF NOT EXISTS file_links (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        file_id INTEGER NOT NULL REFERENCES trip_files(id) ON DELETE CASCADE,
+        reservation_id INTEGER REFERENCES reservations(id) ON DELETE CASCADE,
+        assignment_id INTEGER REFERENCES day_assignments(id) ON DELETE CASCADE,
+        place_id INTEGER REFERENCES places(id) ON DELETE CASCADE,
+        created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+        UNIQUE(file_id, reservation_id),
+        UNIQUE(file_id, assignment_id),
+        UNIQUE(file_id, place_id)
+      )`);
+    },
   ];
 
   if (currentVersion < migrations.length) {
diff --git a/server/src/routes/files.ts b/server/src/routes/files.ts
index 378f074..a48c2d4 100644
--- a/server/src/routes/files.ts
+++ b/server/src/routes/files.ts
@@ -82,7 +82,27 @@ router.get('/', authenticate, (req: Request, res: Response) => {
 
   const where = showTrash ? 'f.trip_id = ? AND f.deleted_at IS NOT NULL' : 'f.trip_id = ? AND f.deleted_at IS NULL';
   const files = db.prepare(`${FILE_SELECT} WHERE ${where} ORDER BY f.starred DESC, f.created_at DESC`).all(tripId) as TripFile[];
-  res.json({ files: files.map(formatFile) });
+
+  // Get all file_links for this trip's files
+  const fileIds = files.map(f => f.id);
+  let linksMap: Record<number, number[]> = {};
+  if (fileIds.length > 0) {
+    const placeholders = fileIds.map(() => '?').join(',');
+    const links = db.prepare(`SELECT file_id, reservation_id, place_id FROM file_links WHERE file_id IN (${placeholders})`).all(...fileIds) as { file_id: number; reservation_id: number | null; place_id: number | null }[];
+    for (const link of links) {
+      if (!linksMap[link.file_id]) linksMap[link.file_id] = [];
+      linksMap[link.file_id].push(link);
+    }
+  }
+
+  res.json({ files: files.map(f => {
+    const fileLinks = linksMap[f.id] || [];
+    return {
+      ...formatFile(f),
+      linked_reservation_ids: fileLinks.filter(l => l.reservation_id).map(l => l.reservation_id),
+      linked_place_ids: fileLinks.filter(l => l.place_id).map(l => l.place_id),
+    };
+  })});
 });
 
 // Upload file
@@ -239,4 +259,55 @@ router.delete('/trash/empty', authenticate, (req: Request, res: Response) => {
   res.json({ success: true, deleted: trashed.length });
 });
 
+// Link a file to a reservation (many-to-many)
+router.post('/:id/link', authenticate, (req: Request, res: Response) => {
+  const authReq = req as AuthRequest;
+  const { tripId, id } = req.params;
+  const { reservation_id, assignment_id, place_id } = req.body;
+
+  const trip = verifyTripOwnership(tripId, authReq.user.id);
+  if (!trip) return res.status(404).json({ error: 'Trip not found' });
+
+  const file = db.prepare('SELECT * FROM trip_files WHERE id = ? AND trip_id = ?').get(id, tripId);
+  if (!file) return res.status(404).json({ error: 'File not found' });
+
+  try {
+    db.prepare('INSERT OR IGNORE INTO file_links (file_id, reservation_id, assignment_id, place_id) VALUES (?, ?, ?, ?)').run(
+      id, reservation_id || null, assignment_id || null, place_id || null
+    );
+  } catch {}
+
+  const links = db.prepare('SELECT * FROM file_links WHERE file_id = ?').all(id);
+  res.json({ success: true, links });
+});
+
+// Unlink a file from a reservation
+router.delete('/:id/link/:linkId', authenticate, (req: Request, res: Response) => {
+  const authReq = req as AuthRequest;
+  const { tripId, id, linkId } = req.params;
+
+  const trip = verifyTripOwnership(tripId, authReq.user.id);
+  if (!trip) return res.status(404).json({ error: 'Trip not found' });
+
+  db.prepare('DELETE FROM file_links WHERE id = ? AND file_id = ?').run(linkId, id);
+  res.json({ success: true });
+});
+
+// Get all links for a file
+router.get('/:id/links', authenticate, (req: Request, res: Response) => {
+  const authReq = req as AuthRequest;
+  const { tripId, id } = req.params;
+
+  const trip = verifyTripOwnership(tripId, authReq.user.id);
+  if (!trip) return res.status(404).json({ error: 'Trip not found' });
+
+  const links = db.prepare(`
+    SELECT fl.*, r.title as reservation_title
+    FROM file_links fl
+    LEFT JOIN reservations r ON fl.reservation_id = r.id
+    WHERE fl.file_id = ?
+  `).all(id);
+  res.json({ links });
+});
+
 export default router;