diff --git a/app/app/Http/Requests/UpdateProjectRequest.php b/app/app/Http/Requests/UpdateProjectRequest.php
index 0d230557..052c643f 100644
--- a/app/app/Http/Requests/UpdateProjectRequest.php
+++ b/app/app/Http/Requests/UpdateProjectRequest.php
@@ -4,6 +4,7 @@ declare(strict_types=1);
 
 namespace App\Http\Requests;
 
+use App\Models\Project;
 use Illuminate\Foundation\Http\FormRequest;
 
 class UpdateProjectRequest extends FormRequest
@@ -16,7 +17,7 @@ class UpdateProjectRequest extends FormRequest
     public function rules(): array
     {
         // signal_type immutable: не валидируется в правилах, controller игнорирует поле
-        return [
+        $rules = [
             'name' => ['sometimes', 'string', 'max:255'],
             'daily_limit_target' => ['sometimes', 'integer', 'min:1', 'max:10000'],
             // Plan 6: subject-level regions[] заменил region_mask/region_mode на API-уровне.
@@ -28,5 +29,23 @@ class UpdateProjectRequest extends FormRequest
             'sms_senders.*' => ['string', 'max:11'],
             'sms_keyword' => ['sometimes', 'nullable', 'string', 'min:1', 'max:50'],
         ];
+
+        // 18.05.2026 UX: редактирование источника (signal_identifier) для site/call.
+        // Регулярки соответствуют StoreProjectRequest (domain + 7\d{10}).
+        // signal_type immutable — берём из текущего проекта по route id.
+        $projectId = $this->route('id');
+        if ($projectId !== null) {
+            $project = Project::find($projectId);
+            if ($project !== null) {
+                if ($project->signal_type === 'site') {
+                    $rules['signal_identifier'] = ['sometimes', 'string', 'regex:/^[a-z0-9][a-z0-9\-]*(\.[a-z0-9][a-z0-9\-]*)*\.[a-z]{2,}$/i'];
+                } elseif ($project->signal_type === 'call') {
+                    $rules['signal_identifier'] = ['sometimes', 'string', 'regex:/^7\d{10}$/'];
+                }
+                // sms: signal_identifier меняется через sms_senders/sms_keyword (см. выше)
+            }
+        }
+
+        return $rules;
     }
 }
diff --git a/app/app/Services/Project/ProjectService.php b/app/app/Services/Project/ProjectService.php
index 4460cbe4..12fe9695 100644
--- a/app/app/Services/Project/ProjectService.php
+++ b/app/app/Services/Project/ProjectService.php
@@ -14,8 +14,9 @@ class ProjectService
     public function update(Project $project, array $data): Project
     {
         // Immutable fields — silently drop (don't 422)
+        // signal_identifier — теперь editable (18.05.2026 ux), валидируется в UpdateProjectRequest.
         unset(
-            $data['tenant_id'], $data['signal_type'], $data['signal_identifier'],
+            $data['tenant_id'], $data['signal_type'],
             $data['delivered_today'], $data['delivered_in_month'],
             $data['supplier_b1_project_id'], $data['supplier_b2_project_id'], $data['supplier_b3_project_id'],
             $data['archived_at'],
@@ -31,7 +32,10 @@ class ProjectService
             ], 422));
         }
 
-        $needsResync = array_key_exists('sms_senders', $data) || array_key_exists('sms_keyword', $data);
+        // Resync на смену любого источник-несущего поля — поставщику нужно знать актуальный домен/телефон/sms.
+        $needsResync = array_key_exists('sms_senders', $data)
+            || array_key_exists('sms_keyword', $data)
+            || array_key_exists('signal_identifier', $data);
 
         $project->update($data);
 
diff --git a/app/phpstan-baseline.neon b/app/phpstan-baseline.neon
index 80f92d5a..6d55aff9 100644
--- a/app/phpstan-baseline.neon
+++ b/app/phpstan-baseline.neon
@@ -1497,7 +1497,7 @@ parameters:
 		-
 			message: '#^Call to an undefined method Pest\\PendingCalls\\TestCall\:\:actingAs\(\)\.$#'
 			identifier: method.notFound
-			count: 8
+			count: 12
 			path: tests/Feature/Plan5/Projects/ProjectsUpdateTest.php
 
 		-
diff --git a/app/resources/js/components/projects/ProjectDetailsDrawer.vue b/app/resources/js/components/projects/ProjectDetailsDrawer.vue
index 36fc5c37..47b6cc68 100644
--- a/app/resources/js/components/projects/ProjectDetailsDrawer.vue
+++ b/app/resources/js/components/projects/ProjectDetailsDrawer.vue
@@ -16,6 +16,7 @@ interface FormState {
     delivery_days_mask: number;
     sms_senders: string[];
     sms_keyword: string;
+    signal_identifier: string;
 }
 
 const form = reactive<FormState>({
@@ -25,6 +26,7 @@ const form = reactive<FormState>({
     delivery_days_mask: 127,
     sms_senders: [],
     sms_keyword: '',
+    signal_identifier: '',
 });
 
 const selectableRegions = REGIONS.filter((r) => r.code !== 0);
@@ -37,6 +39,7 @@ function reseedFromProject(p: Project | null): void {
     form.delivery_days_mask = p.delivery_days_mask ?? 127;
     form.sms_senders = p.sms_senders ?? [];
     form.sms_keyword = p.sms_keyword ?? '';
+    form.signal_identifier = p.signal_identifier ?? '';
 }
 reseedFromProject(props.project);
 
@@ -78,6 +81,10 @@ async function onSave(): Promise<void> {
             regions: form.regions,
             delivery_days_mask: form.delivery_days_mask,
         };
+        // 18.05.2026 ux: редактирование источника проекта.
+        if (props.project.signal_type === 'site' || props.project.signal_type === 'call') {
+            payload.signal_identifier = form.signal_identifier;
+        }
         if (props.project.signal_type === 'sms') {
             payload.sms_senders = form.sms_senders;
             payload.sms_keyword = form.sms_keyword;
@@ -127,6 +134,54 @@ const dayLabels = ['Пн', 'Вт', 'Ср', 'Чт', 'Пт', 'Сб', 'Вс'];
                     <div v-if="errors.name" class="pdd-error" data-testid="pdd-error-name">{{ errors.name[0] }}</div>
                 </label>
 
+                <!-- 18.05.2026 ux: редактирование источника проекта (site/call/sms) -->
+                <label v-if="project?.signal_type === 'site'" class="pdd-field">
+                    <span class="pdd-label">Источник — домен сайта-донора</span>
+                    <input
+                        v-model="form.signal_identifier"
+                        data-testid="pdd-signal-identifier"
+                        class="pdd-input"
+                        placeholder="okna-konkurent.ru"
+                    />
+                    <div v-if="errors.signal_identifier" class="pdd-error" data-testid="pdd-error-signal">
+                        {{ errors.signal_identifier[0] }}
+                    </div>
+                </label>
+                <label v-else-if="project?.signal_type === 'call'" class="pdd-field">
+                    <span class="pdd-label">Источник — телефонный номер донора</span>
+                    <input
+                        v-model="form.signal_identifier"
+                        data-testid="pdd-signal-identifier"
+                        class="pdd-input"
+                        placeholder="79161234567"
+                    />
+                    <div v-if="errors.signal_identifier" class="pdd-error" data-testid="pdd-error-signal">
+                        {{ errors.signal_identifier[0] }}
+                    </div>
+                </label>
+                <div v-else-if="project?.signal_type === 'sms'" class="pdd-field">
+                    <span class="pdd-label">Источник — отправители SMS</span>
+                    <v-combobox
+                        v-model="form.sms_senders"
+                        data-testid="pdd-sms-senders"
+                        multiple
+                        chips
+                        clearable
+                        density="comfortable"
+                        hide-details
+                        placeholder="MTS, BEELINE …"
+                    />
+                    <div v-if="errors.sms_senders" class="pdd-error">{{ errors.sms_senders[0] }}</div>
+                    <span class="pdd-label mt-2">Ключевое слово (опционально)</span>
+                    <input
+                        v-model="form.sms_keyword"
+                        data-testid="pdd-sms-keyword"
+                        class="pdd-input"
+                        placeholder="КРЕДИТ"
+                    />
+                    <div v-if="errors.sms_keyword" class="pdd-error">{{ errors.sms_keyword[0] }}</div>
+                </div>
+
                 <label class="pdd-field">
                     <span class="pdd-label">Лимит лидов в день</span>
                     <input
diff --git a/app/tests/Feature/Plan5/Projects/ProjectsUpdateTest.php b/app/tests/Feature/Plan5/Projects/ProjectsUpdateTest.php
index d0544f68..04f6dc96 100644
--- a/app/tests/Feature/Plan5/Projects/ProjectsUpdateTest.php
+++ b/app/tests/Feature/Plan5/Projects/ProjectsUpdateTest.php
@@ -125,3 +125,61 @@ it('preserves regions when PATCH omits the field (sometimes rule)', function ()
     $response->assertStatus(200);
     expect($project->fresh()->regions)->toBe([82, 83]);
 });
+
+/* ---------------------------------------------------------------------
+ * 18.05.2026 UX-request (Task 5 плана): редактирование источника
+ * (signal_identifier для site/call) — Sync поставщику обязателен.
+ * --------------------------------------------------------------------- */
+
+it('updates signal_identifier for site project + triggers resync', function () {
+    $tenant = Tenant::factory()->create();
+    $user = User::factory()->create(['tenant_id' => $tenant->id]);
+    $project = Project::factory()->create([
+        'tenant_id' => $tenant->id, 'signal_type' => 'site', 'signal_identifier' => 'old.ru',
+    ]);
+
+    $this->actingAs($user)->patchJson("/api/projects/{$project->id}", [
+        'signal_identifier' => 'new-source.ru',
+    ])->assertOk();
+
+    expect($project->fresh()->signal_identifier)->toBe('new-source.ru');
+    Queue::assertPushed(SyncSupplierProjectJob::class);
+});
+
+it('updates signal_identifier for call project (11-digit phone)', function () {
+    $tenant = Tenant::factory()->create();
+    $user = User::factory()->create(['tenant_id' => $tenant->id]);
+    $project = Project::factory()->create([
+        'tenant_id' => $tenant->id, 'signal_type' => 'call', 'signal_identifier' => '79991111111',
+    ]);
+
+    $this->actingAs($user)->patchJson("/api/projects/{$project->id}", [
+        'signal_identifier' => '79992222222',
+    ])->assertOk();
+
+    expect($project->fresh()->signal_identifier)->toBe('79992222222');
+});
+
+it('rejects invalid signal_identifier for site (not a domain)', function () {
+    $tenant = Tenant::factory()->create();
+    $user = User::factory()->create(['tenant_id' => $tenant->id]);
+    $project = Project::factory()->create([
+        'tenant_id' => $tenant->id, 'signal_type' => 'site', 'signal_identifier' => 'ok.ru',
+    ]);
+
+    $this->actingAs($user)->patchJson("/api/projects/{$project->id}", [
+        'signal_identifier' => 'not-a-domain',
+    ])->assertStatus(422)->assertJsonValidationErrors(['signal_identifier']);
+});
+
+it('rejects invalid signal_identifier for call (not 7\d{10})', function () {
+    $tenant = Tenant::factory()->create();
+    $user = User::factory()->create(['tenant_id' => $tenant->id]);
+    $project = Project::factory()->create([
+        'tenant_id' => $tenant->id, 'signal_type' => 'call', 'signal_identifier' => '79991111111',
+    ]);
+
+    $this->actingAs($user)->patchJson("/api/projects/{$project->id}", [
+        'signal_identifier' => '12345',
+    ])->assertStatus(422)->assertJsonValidationErrors(['signal_identifier']);
+});