diff --git a/app/Http/Controllers/Frontdesk/EmployeeController.php b/app/Http/Controllers/Frontdesk/EmployeeController.php
index 488547a..845a724 100644
--- a/app/Http/Controllers/Frontdesk/EmployeeController.php
+++ b/app/Http/Controllers/Frontdesk/EmployeeController.php
@@ -8,11 +8,14 @@ use App\Models\Branch;
 use App\Models\Employee;
 use App\Models\EmployeePresenceEvent;
 use App\Models\Host;
+use App\Models\Member;
+use App\Models\User;
 use App\Services\Frontdesk\EmployeePresenceService;
 use App\Services\Frontdesk\QrCodeService;
 use Illuminate\Http\RedirectResponse;
 use Illuminate\Http\Request;
 use Illuminate\Support\Carbon;
+use Illuminate\Validation\Rule;
 use Illuminate\View\View;
 use Symfony\Component\HttpFoundation\StreamedResponse;
 
@@ -44,6 +47,7 @@ class EmployeeController extends Controller
             'organization' => $organization,
             'branches' => $this->branches($request, $organization->id),
             'hosts' => $this->hosts($request, $organization->id),
+            'linkableUsers' => $this->linkableUsers($request, $organization->id),
         ]);
     }
 
@@ -52,7 +56,7 @@ class EmployeeController extends Controller
         $this->authorizeAbility($request, 'employees.manage');
         $organization = $this->organization($request);
 
-        $validated = $this->validatedEmployee($request);
+        $validated = $this->validatedEmployee($request, $organization->id);
         $pin = $validated['pin'];
         unset($validated['pin']);
 
@@ -77,6 +81,7 @@ class EmployeeController extends Controller
             'employee' => $employee->load('presence'),
             'branches' => $this->branches($request, $employee->organization_id),
             'hosts' => $this->hosts($request, $employee->organization_id),
+            'linkableUsers' => $this->linkableUsers($request, $employee->organization_id, $employee),
         ]);
     }
 
@@ -85,7 +90,7 @@ class EmployeeController extends Controller
         $this->authorizeAbility($request, 'employees.manage');
         $this->authorizeOwner($request, $employee);
 
-        $validated = $this->validatedEmployee($request, updating: true);
+        $validated = $this->validatedEmployee($request, $employee->organization_id, updating: true, employee: $employee);
 
         $payload = $this->employeePayload($validated);
         if (! empty($validated['pin'])) {
@@ -277,12 +282,17 @@ class EmployeeController extends Controller
     }
 
     /** @return array<string, mixed> */
-    protected function validatedEmployee(Request $request, bool $updating = false): array
+    protected function validatedEmployee(Request $request, int $organizationId, bool $updating = false, ?Employee $employee = null): array
     {
         $pinRules = $updating
             ? ['nullable', 'string', 'regex:/^\d{4,6}$/']
             : ['required', 'string', 'regex:/^\d{4,6}$/'];
 
+        $linkableRefs = collect($this->linkableUsers($request, $organizationId, $employee))
+            ->reject(fn (array $user) => $user['taken'])
+            ->pluck('user_ref')
+            ->all();
+
         return $request->validate([
             'employee_code' => ['required', 'string', 'max:32'],
             'full_name' => ['required', 'string', 'max:255'],
@@ -292,10 +302,82 @@ class EmployeeController extends Controller
             'pin' => $pinRules,
             'branch_id' => ['nullable', 'integer'],
             'host_id' => ['nullable', 'integer'],
-            'user_ref' => ['nullable', 'string', 'max:64'],
+            'user_ref' => [
+                'nullable',
+                'string',
+                'max:64',
+                Rule::when(
+                    filled($request->input('user_ref')),
+                    [Rule::in($linkableRefs)]
+                ),
+            ],
         ]);
     }
 
+    /**
+     * Ladill users that can be linked to an employee (team members and linked hosts).
+     *
+     * @return list<array{user_ref: string, label: string, taken: bool}>
+     */
+    protected function linkableUsers(Request $request, int $organizationId, ?Employee $employee = null): array
+    {
+        $ownerRef = $this->ownerRef($request);
+
+        $refs = collect()
+            ->merge(
+                Member::owned($ownerRef)
+                    ->where('organization_id', $organizationId)
+                    ->pluck('user_ref')
+            )
+            ->merge(
+                Host::owned($ownerRef)
+                    ->where('organization_id', $organizationId)
+                    ->whereNotNull('user_ref')
+                    ->pluck('user_ref')
+            )
+            ->merge(
+                Employee::owned($ownerRef)
+                    ->where('organization_id', $organizationId)
+                    ->whereNotNull('user_ref')
+                    ->pluck('user_ref')
+            );
+
+        if ($employee?->user_ref) {
+            $refs->push($employee->user_ref);
+        }
+
+        $refs = $refs->filter()->unique()->values();
+
+        $users = User::query()
+            ->whereIn('public_id', $refs)
+            ->get(['public_id', 'name', 'email'])
+            ->keyBy('public_id');
+
+        $takenRefs = Employee::owned($ownerRef)
+            ->where('organization_id', $organizationId)
+            ->whereNotNull('user_ref')
+            ->when($employee, fn ($query) => $query->where('id', '!=', $employee->id))
+            ->pluck('user_ref')
+            ->flip();
+
+        return $refs
+            ->map(function (string $ref) use ($users, $takenRefs, $employee) {
+                $user = $users->get($ref);
+                $label = $user
+                    ? trim($user->name.' · '.$user->email)
+                    : $ref;
+
+                return [
+                    'user_ref' => $ref,
+                    'label' => $label,
+                    'taken' => $takenRefs->has($ref) && $employee?->user_ref !== $ref,
+                ];
+            })
+            ->sortBy('label', SORT_NATURAL | SORT_FLAG_CASE)
+            ->values()
+            ->all();
+    }
+
     protected function employeePayload(array $validated): array
     {
         $payload = $validated;
diff --git a/resources/views/frontdesk/employees/create.blade.php b/resources/views/frontdesk/employees/create.blade.php
index 14fc6d2..ac25998 100644
--- a/resources/views/frontdesk/employees/create.blade.php
+++ b/resources/views/frontdesk/employees/create.blade.php
@@ -51,10 +51,7 @@
                 </select>
                 <p class="mt-1 text-xs text-slate-500">When stepped out, linked hosts show as unavailable to visitors.</p>
             </div>
-            <div>
-                <label class="block text-sm font-medium text-slate-700">Linked Ladill user (optional)</label>
-                <input type="text" name="user_ref" value="{{ old('user_ref') }}" placeholder="User public ID" class="mt-1 w-full rounded-lg border-slate-300 font-mono text-sm">
-            </div>
+            @include('frontdesk.employees.partials.user-ref-select', ['selectedUserRef' => old('user_ref')])
             <button type="submit" class="btn-primary w-full">Save employee</button>
         </form>
     </div>
diff --git a/resources/views/frontdesk/employees/edit.blade.php b/resources/views/frontdesk/employees/edit.blade.php
index 96220b9..65154e5 100644
--- a/resources/views/frontdesk/employees/edit.blade.php
+++ b/resources/views/frontdesk/employees/edit.blade.php
@@ -49,11 +49,7 @@
                     @endforeach
                 </select>
             </div>
-            <div>
-                <label class="block text-sm font-medium text-slate-700">Linked Ladill user (for mobile step-out)</label>
-                <input type="text" name="user_ref" value="{{ old('user_ref', $employee->user_ref) }}" placeholder="User public ID" class="mt-1 w-full rounded-lg border-slate-300 font-mono text-sm">
-                <p class="mt-1 text-xs text-slate-400">Enables the My presence portal for this employee.</p>
-            </div>
+            @include('frontdesk.employees.partials.user-ref-select', ['selectedUserRef' => old('user_ref', $employee->user_ref)])
             <label class="flex items-center gap-2 text-sm">
                 <input type="checkbox" name="active" value="1" @checked(old('active', $employee->active)) class="rounded border-slate-300">
                 Active (can use kiosk)
diff --git a/resources/views/frontdesk/employees/partials/user-ref-select.blade.php b/resources/views/frontdesk/employees/partials/user-ref-select.blade.php
new file mode 100644
index 0000000..66f0cdc
--- /dev/null
+++ b/resources/views/frontdesk/employees/partials/user-ref-select.blade.php
@@ -0,0 +1,26 @@
+@php
+    $selectedUserRef = old('user_ref', $selectedUserRef ?? '');
+@endphp
+
+<div>
+    <label class="block text-sm font-medium text-slate-700">Linked Ladill user (optional)</label>
+    <select name="user_ref" class="mt-1 w-full rounded-lg border-slate-300 text-sm">
+        <option value="">None</option>
+        @foreach ($linkableUsers as $linkableUser)
+            <option value="{{ $linkableUser['user_ref'] }}"
+                    @selected($selectedUserRef === $linkableUser['user_ref'])
+                    @disabled($linkableUser['taken'] && $selectedUserRef !== $linkableUser['user_ref'])>
+                {{ $linkableUser['label'] }}@if ($linkableUser['taken']) (linked to another employee) @endif
+            </option>
+        @endforeach
+    </select>
+    @if (count($linkableUsers) === 0)
+        <p class="mt-1 text-xs text-amber-700">
+            No Ladill users available yet.
+            <a href="{{ route('frontdesk.members.create') }}" class="font-medium underline">Add a team member</a>
+            so they can be linked here.
+        </p>
+    @else
+        <p class="mt-1 text-xs text-slate-500">Enables the My presence portal when this person signs in with the selected Ladill account.</p>
+    @endif
+</div>