diff --git a/backend/src/services/contract.service.ts b/backend/src/services/contract.service.ts
index 9afbff3f..21c07ec9 100644
--- a/backend/src/services/contract.service.ts
+++ b/backend/src/services/contract.service.ts
@@ -102,6 +102,22 @@ export async function getAllContracts(filters: ContractFilters) {
             simCards: { select: { phoneNumber: true, isMain: true } },
           },
         },
+        // 2026-07-04: für Vertragsauswahl-Labels brauchen wir überall
+        // die Zählernummer (Strom/Gas) und die erste Festnetznummer
+        // (Internet). Beides light-select, damit das Payload klein bleibt.
+        energyDetails: {
+          select: {
+            meter: { select: { id: true, meterNumber: true } },
+          },
+        },
+        internetDetails: {
+          select: {
+            phoneNumbers: {
+              select: { phoneNumber: true, isMain: true },
+              orderBy: { id: 'asc' },
+            },
+          },
+        },
         carInsuranceDetails: { select: { licensePlate: true } },
       },
     }),
diff --git a/frontend/src/components/email/AssignToContractModal.tsx b/frontend/src/components/email/AssignToContractModal.tsx
index d56f7fb0..2344bcec 100644
--- a/frontend/src/components/email/AssignToContractModal.tsx
+++ b/frontend/src/components/email/AssignToContractModal.tsx
@@ -4,6 +4,7 @@ import Modal from '../ui/Modal';
 import Button from '../ui/Button';
 import { contractApi, cachedEmailApi, CachedEmail } from '../../services/api';
 import { formatDate } from '../../utils/dateFormat';
+import { buildContractLabelParts } from '../../utils/contractLabel';
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
 
 interface AssignToContractModalProps {
@@ -147,6 +148,14 @@ export default function AssignToContractModal({
                       {contract.contractCategory?.name}
                       {contract.provider && ` - ${contract.provider.name}`}
                     </div>
+                    {(() => {
+                      const parts = buildContractLabelParts(contract);
+                      return parts.extras.length > 0 ? (
+                        <div className="text-xs text-gray-500 truncate">
+                          {parts.extras.join(' · ')}
+                        </div>
+                      ) : null;
+                    })()}
                     <div className="text-xs text-gray-500">
                       Start: {formatDateOrDash(contract.startDate)}
                     </div>
diff --git a/frontend/src/pages/Dashboard.tsx b/frontend/src/pages/Dashboard.tsx
index 4f937733..8f89df43 100644
--- a/frontend/src/pages/Dashboard.tsx
+++ b/frontend/src/pages/Dashboard.tsx
@@ -3,6 +3,7 @@ import { useQuery, useQueryClient } from '@tanstack/react-query';
 import { Link, useNavigate } from 'react-router-dom';
 import { useAuth } from '../context/AuthContext';
 import { customerApi, contractApi, contractTaskApi, appSettingsApi } from '../services/api';
+import { buildContractLabelParts } from '../utils/contractLabel';
 import Card from '../components/ui/Card';
 import Button from '../components/ui/Button';
 import Input from '../components/ui/Input';
@@ -572,6 +573,14 @@ function CreateSupportTicketModal({
                     {contract.providerName || 'Kein Anbieter'}
                     {contract.tariffName && ` - ${contract.tariffName}`}
                   </div>
+                  {(() => {
+                    const parts = buildContractLabelParts(contract);
+                    return parts.extras.length > 0 ? (
+                      <div className="text-xs text-gray-400 truncate">
+                        {parts.extras.join(' · ')}
+                      </div>
+                    ) : null;
+                  })()}
                 </div>
               ))
             ) : (
diff --git a/frontend/src/pages/contracts/ContractForm.tsx b/frontend/src/pages/contracts/ContractForm.tsx
index 7da15343..8df2bf6a 100644
--- a/frontend/src/pages/contracts/ContractForm.tsx
+++ b/frontend/src/pages/contracts/ContractForm.tsx
@@ -11,6 +11,7 @@ import Input from '../../components/ui/Input';
 import Select from '../../components/ui/Select';
 import CopyButton from '../../components/ui/CopyButton';
 import CustomerInfoModal from '../../components/contracts/CustomerInfoModal';
+import { buildContractLabelParts } from '../../utils/contractLabel';
 import type { ContractType } from '../../types';
 import { formatDate } from '../../utils/dateFormat';
 import { useProviderSettings } from '../../hooks/useProviderSettings';
@@ -878,10 +879,15 @@ export default function ContractForm() {
               <Select
                 label="Vorgänger-Vertrag"
                 {...register('previousContractId')}
-                options={predecessorContracts.map((c) => ({
-                  value: c.id,
-                  label: `${c.contractNumber} (${c.type}${c.startDate ? ` - ${formatDate(c.startDate)}` : ''})`,
-                }))}
+                options={predecessorContracts.map((c) => {
+                  const parts = buildContractLabelParts(c);
+                  const dateHint = c.startDate ? ` – ${formatDate(c.startDate)}` : '';
+                  const suffix = parts.extras.length > 0 ? ` · ${parts.extras.join(' · ')}` : '';
+                  return {
+                    value: c.id,
+                    label: `${c.contractNumber} (${c.type}${dateHint})${suffix}`,
+                  };
+                })}
                 placeholder="Keinen Vorgänger auswählen"
               />
             )}
diff --git a/frontend/src/pages/settings/PdfTemplates.tsx b/frontend/src/pages/settings/PdfTemplates.tsx
index 5d785a32..956ea0bf 100644
--- a/frontend/src/pages/settings/PdfTemplates.tsx
+++ b/frontend/src/pages/settings/PdfTemplates.tsx
@@ -3,6 +3,7 @@ import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { useNavigate } from 'react-router-dom';
 import { pdfTemplateApi, contractApi, authApi } from '../../services/api';
 import type { PdfTemplate, CrmField, Contract } from '../../types';
+import { buildContractLabelParts } from '../../utils/contractLabel';
 import Card from '../../components/ui/Card';
 import Button from '../../components/ui/Button';
 import Input from '../../components/ui/Input';
@@ -475,13 +476,23 @@ function TestPreviewModal({ template, onClose }: { template: PdfTemplate; onClos
                   selectedContractId === c.id ? 'bg-blue-50 border-blue-200' : ''
                 }`}
               >
-                <div>
-                  <span className="font-mono font-medium">{c.contractNumber}</span>
-                  {c.customer && (
-                    <span className="text-gray-500 ml-2">
-                      {c.customer.companyName || `${c.customer.firstName} ${c.customer.lastName}`}
-                    </span>
-                  )}
+                <div className="flex-1 min-w-0">
+                  <div>
+                    <span className="font-mono font-medium">{c.contractNumber}</span>
+                    {c.customer && (
+                      <span className="text-gray-500 ml-2">
+                        {c.customer.companyName || `${c.customer.firstName} ${c.customer.lastName}`}
+                      </span>
+                    )}
+                  </div>
+                  {(() => {
+                    const parts = buildContractLabelParts(c);
+                    return parts.extras.length > 0 ? (
+                      <div className="text-xs text-gray-400 truncate">
+                        {parts.extras.join(' · ')}
+                      </div>
+                    ) : null;
+                  })()}
                 </div>
                 <Badge variant="default">{c.type}</Badge>
               </button>
diff --git a/frontend/src/pages/tasks/TaskList.tsx b/frontend/src/pages/tasks/TaskList.tsx
index c4ea6668..7108fe82 100644
--- a/frontend/src/pages/tasks/TaskList.tsx
+++ b/frontend/src/pages/tasks/TaskList.tsx
@@ -25,6 +25,7 @@ import {
   Trash2,
 } from 'lucide-react';
 import type { ContractTask, ContractTaskStatus, Contract, Customer, ContractTaskSubtask } from '../../types';
+import { buildContractLabelParts } from '../../utils/contractLabel';
 
 const statusLabels: Record<ContractTaskStatus, string> = {
   OPEN: 'Offen',
@@ -687,6 +688,14 @@ function CreateSupportTicketModal({
                         {contract.providerName || 'Kein Anbieter'}
                         {contract.tariffName && ` - ${contract.tariffName}`}
                       </div>
+                      {(() => {
+                        const parts = buildContractLabelParts(contract);
+                        return parts.extras.length > 0 ? (
+                          <div className="text-xs text-gray-400 truncate">
+                            {parts.extras.join(' · ')}
+                          </div>
+                        ) : null;
+                      })()}
                     </div>
                   </div>
                 );
@@ -915,6 +924,14 @@ function CreateTaskModal({
                       {contract.providerName || 'Kein Anbieter'}
                       {contract.tariffName && ` - ${contract.tariffName}`}
                     </div>
+                    {(() => {
+                      const parts = buildContractLabelParts(contract);
+                      return parts.extras.length > 0 ? (
+                        <div className="text-xs text-gray-400 truncate">
+                          {parts.extras.join(' · ')}
+                        </div>
+                      ) : null;
+                    })()}
                   </div>
                 ))
               ) : (
diff --git a/frontend/src/utils/contractLabel.ts b/frontend/src/utils/contractLabel.ts
new file mode 100644
index 00000000..eb87bb9a
--- /dev/null
+++ b/frontend/src/utils/contractLabel.ts
@@ -0,0 +1,108 @@
+// Einheitliches Label für Vertragsauswahl-Listen (Assign-Modals, Neue-
+// Aufgabe, Neue-Support-Anfrage, Vorgänger-Vertrag, PDF-Vorlage-Test).
+//
+// User-Wunsch 2026-07-04: überall, wo man einen Vertrag aus einer Liste
+// wählt, sollen zusätzlich zur Vertragsnummer folgende Infos sichtbar
+// sein, sofern vorhanden:
+//   - Kundennummer (interne CRM-Nummer des Kunden)
+//   - Vertragsnummer beim Anbieter (contractNumberAtProvider)
+//   - Zählernummer (Strom/Gas, aus energyDetails.meter)
+//   - Mobilfunknummer (main SIM) bei Mobilfunk
+//   - Erste Festnetznummer bei Internet-Verträgen
+//
+// Der Helper liefert entweder eine flache Textzeile
+// (`formatContractLabel`) oder ein strukturiertes Objekt mit Bestandteilen
+// (`buildContractLabelParts`), damit UI-Views mit mehreren Zeilen /
+// Badges das gleiche Modell teilen.
+
+import type { Contract } from '../types';
+
+export interface ContractLabelParts {
+  /** Interne Vertragsnummer (immer vorhanden). */
+  contractNumber: string;
+  /** Anbietername oder null, wenn keiner gesetzt ist. */
+  providerName: string | null;
+  /** Tarifname oder null. */
+  tariffName: string | null;
+  /**
+   * Kurze Zusatzinfos, jede nur wenn Daten existieren – z.B.
+   * `Kdnr. 12345`, `Anbieter-Vtr. VG-2026`, `Zähler 1EMH…`,
+   * `Mobil +49 …`, `Festnetz +49 …`.
+   */
+  extras: string[];
+}
+
+/**
+ * Fischt die relevanten Zusatzfelder aus dem Contract raus. Fehlende
+ * Felder werden übersprungen – das Ergebnis passt sich automatisch dem
+ * Vertragstyp an (Zählernummer nur bei Strom/Gas, Mobilfunknr nur bei
+ * MOBILE, Festnetznr nur bei INTERNET etc.).
+ */
+export function buildContractLabelParts(contract: Contract): ContractLabelParts {
+  const providerName =
+    contract.provider?.name ??
+    (contract.providerName ? contract.providerName : null);
+  const tariffName =
+    contract.tariff?.name ??
+    (contract.tariffName ? contract.tariffName : null);
+
+  const extras: string[] = [];
+
+  const customerNumber = contract.customer?.customerNumber;
+  if (customerNumber) {
+    extras.push(`Kdnr. ${customerNumber}`);
+  }
+
+  const providerContractNumber = contract.contractNumberAtProvider;
+  if (providerContractNumber) {
+    extras.push(`Anbieter-Vtr. ${providerContractNumber}`);
+  }
+
+  const meterNumber = contract.energyDetails?.meter?.meterNumber;
+  if (meterNumber) {
+    extras.push(`Zähler ${meterNumber}`);
+  }
+
+  // Mobilfunk: Main-SIM-Nummer bevorzugt, sonst erste vorhandene.
+  const simCards = contract.mobileDetails?.simCards ?? [];
+  if (simCards.length > 0) {
+    const mainSim = simCards.find((s) => s.isMain && s.phoneNumber) ?? simCards.find((s) => !!s.phoneNumber);
+    if (mainSim?.phoneNumber) {
+      extras.push(`Mobil ${mainSim.phoneNumber}`);
+    } else if (contract.mobileDetails?.phoneNumber) {
+      extras.push(`Mobil ${contract.mobileDetails.phoneNumber}`);
+    }
+  } else if (contract.mobileDetails?.phoneNumber) {
+    extras.push(`Mobil ${contract.mobileDetails.phoneNumber}`);
+  }
+
+  // Festnetz: Main-Nummer bevorzugt, sonst erste vorhandene.
+  const phones = contract.internetDetails?.phoneNumbers ?? [];
+  if (phones.length > 0) {
+    const mainPhone = phones.find((p) => p.isMain && p.phoneNumber) ?? phones.find((p) => !!p.phoneNumber);
+    if (mainPhone?.phoneNumber) {
+      extras.push(`Festnetz ${mainPhone.phoneNumber}`);
+    }
+  }
+
+  return {
+    contractNumber: contract.contractNumber,
+    providerName,
+    tariffName,
+    extras,
+  };
+}
+
+/**
+ * Flach-String-Version für <Select>-Options:
+ * `GAS-XYZ · Anbieter · Tarif · Kdnr. 123 · Zähler 1EMH…`
+ * Trenner: ` · ` (schmale Bullets ohne Sonderzeichen im URL/DOM).
+ */
+export function formatContractLabel(contract: Contract): string {
+  const parts = buildContractLabelParts(contract);
+  const chunks: string[] = [parts.contractNumber];
+  if (parts.providerName) chunks.push(parts.providerName);
+  if (parts.tariffName) chunks.push(parts.tariffName);
+  chunks.push(...parts.extras);
+  return chunks.join(' · ');
+}