diff --git a/app/Http/Requests/Notice/NoticeUpdateRequest.php b/app/Http/Requests/Notice/NoticeUpdateRequest.php
index 25b4aa03..84da0cbd 100644
--- a/app/Http/Requests/Notice/NoticeUpdateRequest.php
+++ b/app/Http/Requests/Notice/NoticeUpdateRequest.php
@@ -40,7 +40,7 @@ public function rules(): array
             ],
 
             'instrument_type' => [
-                'sometimes',
+                'required',
                 function (string $attribute, mixed $value, \Closure $fail) use ($notice) {
                     if ($notice) {
                         $currentValue = $notice->instrument_type instanceof \BackedEnum
@@ -52,9 +52,7 @@ function (string $attribute, mixed $value, \Closure $fail) use ($notice) {
                         }
                     }
                 },
-                Rule::when(fn () => filled($this->input('instrument_type')), [
-                    new Enum(InstrumentType::class),
-                ]),
+                new Enum(InstrumentType::class),
             ],
 
             'name' => ['sometimes', 'string'],
diff --git a/app/Services/NoticeService.php b/app/Services/NoticeService.php
index f50aa607..048a4b1c 100644
--- a/app/Services/NoticeService.php
+++ b/app/Services/NoticeService.php
@@ -92,30 +92,34 @@ public function update(Notice $notice, array $data): Notice
     {
         return DB::transaction(function () use ($notice, $data) {
             if (array_key_exists('instrument_type', $data)) {
-                $projectIds = Project::where('notice_id', $notice->id)
-                    ->orderBy('id')
-                    ->lockForUpdate()
-                    ->pluck('id');
+                if (is_null($data['instrument_type'])) {
+                    unset($data['instrument_type']);
+                } else {
+                    $projectIds = Project::where('notice_id', $notice->id)
+                        ->orderBy('id')
+                        ->lockForUpdate()
+                        ->pluck('id');
 
-                $lockedNotice = Notice::where('id', $notice->id)
-                    ->lockForUpdate()
-                    ->first();
+                    $lockedNotice = Notice::where('id', $notice->id)
+                        ->lockForUpdate()
+                        ->first();
 
-                $currentType = $lockedNotice->instrument_type instanceof \BackedEnum
-                    ? $lockedNotice->instrument_type->value
-                    : $lockedNotice->instrument_type;
+                    $currentType = $lockedNotice->instrument_type instanceof \BackedEnum
+                        ? $lockedNotice->instrument_type->value
+                        : $lockedNotice->instrument_type;
 
-                $instrumentTypeChanged = $data['instrument_type'] !== $currentType;
+                    $instrumentTypeChanged = $data['instrument_type'] !== $currentType;
 
-                $lockedNotice->update($data);
+                    $lockedNotice->update($data);
 
-                if ($instrumentTypeChanged) {
-                    Formalization::whereIn('project_id', $projectIds)
-                        ->lockForUpdate()
-                        ->update(['term_number' => null]);
-                }
+                    if ($instrumentTypeChanged) {
+                        Formalization::whereIn('project_id', $projectIds)
+                            ->lockForUpdate()
+                            ->update(['term_number' => null]);
+                    }
 
-                return $lockedNotice;
+                    return $lockedNotice;
+                }
             }
 
             $notice->update($data);
diff --git a/resources/js/Pages/Notices/NupDialog.vue b/resources/js/Pages/Notices/NupDialog.vue
index aec47870..e360b3e8 100644
--- a/resources/js/Pages/Notices/NupDialog.vue
+++ b/resources/js/Pages/Notices/NupDialog.vue
@@ -105,12 +105,7 @@ const valorExtenso = computed(() => {
                         </v-col>
 
                         <v-col cols="12" md="6">
-                            <FormField
-                                label="Tipo de instrumento"
-                                :error="form.errors.instrument_type"
-                                required
-                                clearable
-                            >
+                            <FormField label="Tipo de instrumento" :error="form.errors.instrument_type" required>
                                 <SelectField
                                     v-model="form.instrument_type"
                                     :items="instrumentTypes"
diff --git a/resources/js/Pages/Projects/Partials/ProjectNoticeEdit.vue b/resources/js/Pages/Projects/Partials/ProjectNoticeEdit.vue
index bb00b078..a4707321 100644
--- a/resources/js/Pages/Projects/Partials/ProjectNoticeEdit.vue
+++ b/resources/js/Pages/Projects/Partials/ProjectNoticeEdit.vue
@@ -75,6 +75,7 @@ const saveAll = () => {
                     :items="instrumentTypes"
                     :error="form.errors.instrument_type"
                     data-cy="instrument-type-show-all-information"
+                    required
                 />
                 <EditableField
                     v-model="form.process_manager"
diff --git a/tests/Feature/Notice/UpdateValidationTest.php b/tests/Feature/Notice/UpdateValidationTest.php
index 197b077a..5a303949 100644
--- a/tests/Feature/Notice/UpdateValidationTest.php
+++ b/tests/Feature/Notice/UpdateValidationTest.php
@@ -2,6 +2,7 @@
 
 namespace Tests\Feature\Notice;
 
+use App\Enums\InstrumentType;
 use App\Enums\MonitoringReportRequestDeadline;
 use App\Models\Notice;
 use App\Models\User;
@@ -44,10 +45,15 @@ public function test_user_without_role_cannot_update_notice(): void
 
     public function test_fomentation_role_can_update_notice(): void
     {
-        $notice = Notice::factory()->create();
+        $notice = Notice::factory()->create([
+            'instrument_type' => InstrumentType::EXECUCAO_CULTURAL->value,
+        ]);
 
         $this->actingAs($this->userWithRole)
-            ->patch(route('notices.update', $notice), ['nup' => $notice->nup])
+            ->patch(route('notices.update', $notice), [
+                'nup' => $notice->nup,
+                'instrument_type' => $notice->instrument_type,
+            ])
             ->assertRedirect();
     }
 
@@ -55,10 +61,15 @@ public function test_super_admin_role_can_update_notice(): void
     {
         $admin = User::factory()->create();
         $admin->assignRole('super_admin');
-        $notice = Notice::factory()->create();
+        $notice = Notice::factory()->create([
+            'instrument_type' => InstrumentType::EXECUCAO_CULTURAL->value,
+        ]);
 
         $this->actingAs($admin)
-            ->patch(route('notices.update', $notice), ['nup' => $notice->nup])
+            ->patch(route('notices.update', $notice), [
+                'nup' => $notice->nup,
+                'instrument_type' => $notice->instrument_type,
+            ])
             ->assertRedirect();
     }
 
@@ -72,11 +83,13 @@ public function test_budget_allocation_nup_must_be_unique(): void
 
         $notice = Notice::factory()->create([
             'budget_allocation_nup' => '99999.000001/2024-99',
+            'instrument_type' => InstrumentType::EXECUCAO_CULTURAL->value,
         ]);
 
         $this->actingAs($this->userWithRole)
             ->patch(route('notices.update', $notice), [
                 'budget_allocation_nup' => $existing->budget_allocation_nup,
+                'instrument_type' => $notice->instrument_type,
             ])
             ->assertSessionHasErrors('budget_allocation_nup');
     }
@@ -85,11 +98,13 @@ public function test_budget_allocation_nup_can_be_updated_to_same_value(): void
     {
         $notice = Notice::factory()->create([
             'budget_allocation_nup' => '12345.678901/2024-01',
+            'instrument_type' => InstrumentType::EXECUCAO_CULTURAL->value,
         ]);
 
         $this->actingAs($this->userWithRole)
             ->patch(route('notices.update', $notice), [
                 'budget_allocation_nup' => $notice->budget_allocation_nup,
+                'instrument_type' => $notice->instrument_type,
             ])
             ->assertRedirect()
             ->assertSessionHasNoErrors();
@@ -103,22 +118,27 @@ public function test_nup_must_be_unique(): void
 
         $notice = Notice::factory()->create([
             'nup' => '99999.000001/2024-99',
+            'instrument_type' => InstrumentType::EXECUCAO_CULTURAL->value,
         ]);
 
         $this->actingAs($this->userWithRole)
             ->patch(route('notices.update', $notice), [
                 'nup' => $existing->nup,
+                'instrument_type' => $notice->instrument_type,
             ])
             ->assertSessionHasErrors('nup');
     }
 
     public function test_monitoring_report_request_deadline_can_be_updated(): void
     {
-        $notice = Notice::factory()->create();
+        $notice = Notice::factory()->create([
+            'instrument_type' => InstrumentType::EXECUCAO_CULTURAL->value,
+        ]);
 
         $this->actingAs($this->userWithRole)
             ->patch(route('notices.update', $notice), [
                 'monitoring_report_request_deadline' => MonitoringReportRequestDeadline::MECENAS->value,
+                'instrument_type' => $notice->instrument_type,
             ])
             ->assertRedirect()
             ->assertSessionHasNoErrors();
@@ -131,12 +151,44 @@ public function test_monitoring_report_request_deadline_can_be_updated(): void
 
     public function test_monitoring_report_request_deadline_must_be_a_supported_value(): void
     {
-        $notice = Notice::factory()->create();
+        $notice = Notice::factory()->create([
+            'instrument_type' => InstrumentType::EXECUCAO_CULTURAL->value,
+        ]);
 
         $this->actingAs($this->userWithRole)
             ->patch(route('notices.update', $notice), [
                 'monitoring_report_request_deadline' => 'INVALIDO',
+                'instrument_type' => $notice->instrument_type,
             ])
             ->assertSessionHasErrors('monitoring_report_request_deadline');
     }
+
+    // ─── Instrument Type ────────────────────────────────────────────────────────
+
+    public function test_instrument_type_is_required_on_update(): void
+    {
+        $notice = Notice::factory()->create([
+            'instrument_type' => InstrumentType::EXECUCAO_CULTURAL->value,
+        ]);
+
+        $this->actingAs($this->userWithRole)
+            ->patch(route('notices.update', $notice), [
+                'nup' => $notice->nup,
+                // instrument_type omitido intencionalmente
+            ])
+            ->assertSessionHasErrors('instrument_type');
+    }
+
+    public function test_instrument_type_cannot_be_null_on_update(): void
+    {
+        $notice = Notice::factory()->create([
+            'instrument_type' => InstrumentType::EXECUCAO_CULTURAL->value,
+        ]);
+
+        $this->actingAs($this->userWithRole)
+            ->patch(route('notices.update', $notice), [
+                'instrument_type' => null,
+            ])
+            ->assertSessionHasErrors('instrument_type');
+    }
 }