diff --git a/VERSION.txt b/VERSION.txt
index dbf3366489b1..c9c84322d739 100644
--- a/VERSION.txt
+++ b/VERSION.txt
@@ -1 +1 @@
-5.0.22
+5.0.23
diff --git a/app/Http/Requests/Task/StoreTaskRequest.php b/app/Http/Requests/Task/StoreTaskRequest.php
index 78cf87402e94..6bd1bce41387 100644
--- a/app/Http/Requests/Task/StoreTaskRequest.php
+++ b/app/Http/Requests/Task/StoreTaskRequest.php
@@ -38,8 +38,8 @@ class StoreTaskRequest extends Request
     {
         $rules = [];
         
-        $rules['number'] = Rule::unique('tasks')
-                                ->where('company_id', auth()->user()->company()->id);
+        if(isset($this->number))
+            $rules['number'] = Rule::unique('tasks')->where('company_id', auth()->user()->company()->id);
     
        return $this->globalRules($rules);
     }
diff --git a/app/Http/Requests/Task/UpdateTaskRequest.php b/app/Http/Requests/Task/UpdateTaskRequest.php
index 57fcda98bb9c..16a1e3882e1f 100644
--- a/app/Http/Requests/Task/UpdateTaskRequest.php
+++ b/app/Http/Requests/Task/UpdateTaskRequest.php
@@ -38,9 +38,8 @@ class UpdateTaskRequest extends Request
     {
         $rules = [];
 
-        $rules['number'] = Rule::unique('tasks')
-                                ->where('company_id', auth()->user()->company()->id)
-                                ->ignore($this->task->id);
+        if(isset($this->number))
+            $rules['number'] = Rule::unique('tasks')->where('company_id', auth()->user()->company()->id)->ignore($this->task->id);
 
         return $this->globalRules($rules);
     }
diff --git a/app/Models/Invoice.php b/app/Models/Invoice.php
index 1fc5e4d7084d..d850444409f3 100644
--- a/app/Models/Invoice.php
+++ b/app/Models/Invoice.php
@@ -209,6 +209,15 @@ class Invoice extends BaseModel
         return $this->hasMany(Credit::class);
     }
 
+    public function tasks()
+    {
+        return $this->hasMany(Task::class);
+    }
+
+    public function expenses()
+    {
+        return $this->hasMany(Expense::class);
+    }
     /**
      * Service entry points.
      */
diff --git a/app/Repositories/BaseRepository.php b/app/Repositories/BaseRepository.php
index 510decebc161..8a586923e4b8 100644
--- a/app/Repositories/BaseRepository.php
+++ b/app/Repositories/BaseRepository.php
@@ -314,6 +314,7 @@ class BaseRepository
             if (($state['finished_amount'] != $state['starting_amount']) && ($model->status_id != Invoice::STATUS_DRAFT)) {
                 $model->ledger()->updateInvoiceBalance(($state['finished_amount'] - $state['starting_amount']));
                 $model->client->service()->updateBalance(($state['finished_amount'] - $state['starting_amount']))->save();
+                $model->service()->linkEntities()->save();
             }
 
             if (! $model->design_id) {
diff --git a/app/Services/Invoice/InvoiceService.php b/app/Services/Invoice/InvoiceService.php
index da1393e21409..0a17c929ea44 100644
--- a/app/Services/Invoice/InvoiceService.php
+++ b/app/Services/Invoice/InvoiceService.php
@@ -14,8 +14,10 @@ namespace App\Services\Invoice;
 use App\Jobs\Entity\CreateEntityPdf;
 use App\Jobs\Util\UnlinkFile;
 use App\Models\CompanyGateway;
+use App\Models\Expense;
 use App\Models\Invoice;
 use App\Models\Payment;
+use App\Models\Task;
 use App\Services\Client\ClientService;
 use App\Services\Invoice\ApplyNumber;
 use App\Services\Invoice\ApplyPayment;
@@ -30,10 +32,13 @@ use App\Services\Invoice\MarkInvoicePaid;
 use App\Services\Invoice\MarkSent;
 use App\Services\Invoice\TriggeredActions;
 use App\Services\Invoice\UpdateBalance;
+use App\Utils\Traits\MakesHash;
 use Illuminate\Support\Carbon;
 
 class InvoiceService
 {
+    use MakesHash;
+
     private $invoice;
 
     protected $client_service;
@@ -328,6 +333,30 @@ class InvoiceService
         return $this;
     }
 
+    public function linkEntities()
+    {
+        //set all task.invoice_ids = 0
+        $this->invoice->tasks()->update(['invoice_id' => null]);
+
+        //set all tasks.invoice_ids = x with the current  line_items
+        $tasks = collect($this->invoice->line_items)->map(function ($item){
+
+            if(isset($item->task_id))
+                $item->task_id = $this->decodePrimaryKey($item->task_id);
+
+            if(isset($item->expense_id))
+                $item->expense_id = $this->decodePrimaryKey($item->expense_id);
+
+            return $item;
+
+        });
+
+        Task::whereIn('id',$tasks->pluck('task_id'))->update(['invoice_id' => $this->invoice->id]);
+        Expense::whereIn('id',$tasks->pluck('expense_id'))->update(['invoice_id' => $this->invoice->id]);
+
+        return $this;
+    }
+
     /**
      * Saves the invoice.
      * @return Invoice object
diff --git a/app/Services/Invoice/MarkInvoiceDeleted.php b/app/Services/Invoice/MarkInvoiceDeleted.php
index 2d98ed2ed4fb..7d245d64b487 100644
--- a/app/Services/Invoice/MarkInvoiceDeleted.php
+++ b/app/Services/Invoice/MarkInvoiceDeleted.php
@@ -53,6 +53,10 @@ class MarkInvoiceDeleted extends AbstractService
 
         $this->invoice->number = $number;
 
+        //wipe references to invoices from related entities.
+        $this->invoice->tasks()->update(['invoice_id' => null]);
+        $this->invoice->expenses()->update(['invoice_id' => null]);
+
         return $this->invoice;
     }
 
diff --git a/app/Utils/Traits/Notifications/UserNotifies.php b/app/Utils/Traits/Notifications/UserNotifies.php
index 7ff3b0a1cf60..7a9f7c22b38c 100644
--- a/app/Utils/Traits/Notifications/UserNotifies.php
+++ b/app/Utils/Traits/Notifications/UserNotifies.php
@@ -41,7 +41,7 @@ trait UserNotifies
 
     public function findUserEntityNotificationType($entity, $company_user, $required_permissions) :array
     {
-        if ($this->migrationRunning($company_user)) {
+        if ($company_user->company->is_disabled) {
             return [];
         }
 
@@ -65,7 +65,7 @@ trait UserNotifies
 
     public function findCompanyUserNotificationType($company_user, $required_permissions) :array
     {
-        if ($this->migrationRunning($company_user)) {
+        if ($company_user->company->is_disabled) {
             return [];
         }
 
diff --git a/config/ninja.php b/config/ninja.php
index 2ea9e28e7557..a304af58b545 100644
--- a/config/ninja.php
+++ b/config/ninja.php
@@ -12,7 +12,7 @@ return [
     'require_https' => env('REQUIRE_HTTPS', true),
     'app_url' => rtrim(env('APP_URL', ''), '/').'/',
     'app_domain' => env('APP_DOMAIN', ''),
-    'app_version' => '5.0.22',
+    'app_version' => '5.0.23',
     'minimum_client_version' => '5.0.16',
     'terms_version' => '1.0.1',
     'api_secret' => env('API_SECRET', ''),
diff --git a/database/factories/ExpenseFactory.php b/database/factories/ExpenseFactory.php
index ea5716ca6402..685bead9803e 100644
--- a/database/factories/ExpenseFactory.php
+++ b/database/factories/ExpenseFactory.php
@@ -42,6 +42,7 @@ class ExpenseFactory extends Factory
             'public_notes' => $this->faker->text(50),
             'private_notes' => $this->faker->text(50),
             'transaction_reference' => $this->faker->text(5),
+            'invoice_id' => null,
         ];
     }
 }
diff --git a/database/factories/TaskFactory.php b/database/factories/TaskFactory.php
index 759114c9d8f2..b18016f3e14a 100644
--- a/database/factories/TaskFactory.php
+++ b/database/factories/TaskFactory.php
@@ -33,6 +33,7 @@ class TaskFactory extends Factory
 	    {
 	    return [
 	        'description' => $this->faker->text(50),
+            'invoice_id' => null,
 	    ];
 	}
 }
\ No newline at end of file
diff --git a/tests/Feature/InvoiceLinkTasksTest.php b/tests/Feature/InvoiceLinkTasksTest.php
new file mode 100644
index 000000000000..3a2c7b1eed84
--- /dev/null
+++ b/tests/Feature/InvoiceLinkTasksTest.php
@@ -0,0 +1,77 @@
+<?php
+/**
+ * Invoice Ninja (https://invoiceninja.com).
+ *
+ * @link https://github.com/invoiceninja/invoiceninja source repository
+ *
+ * @copyright Copyright (c) 2020. Invoice Ninja LLC (https://invoiceninja.com)
+ *
+ * @license https://opensource.org/licenses/AAL
+ */
+namespace Tests\Feature;
+
+use App\DataMapper\ClientSettings;
+use App\DataMapper\CompanySettings;
+use App\Factory\InvoiceFactory;
+use App\Models\Account;
+use App\Models\Client;
+use App\Models\ClientContact;
+use App\Models\Invoice;
+use App\Models\Task;
+use App\Utils\Traits\MakesHash;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Foundation\Testing\DatabaseTransactions;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Foundation\Testing\WithFaker;
+use Illuminate\Support\Facades\Log;
+use Illuminate\Support\Facades\Session;
+use Tests\MockAccountData;
+use Tests\TestCase;
+
+/**
+ * @test
+ */
+class InvoiceLinkTasksTest extends TestCase
+{
+    use MakesHash;
+    use DatabaseTransactions;
+    use MockAccountData;
+
+    public function setUp() :void
+    {
+        parent::setUp();
+
+        Session::start();
+
+        $this->faker = \Faker\Factory::create();
+
+        Model::reguard();
+
+        $this->makeTestData();
+    }
+
+    public function testMapCreation()
+    {
+        $temp_invoice_id = $this->invoice->id;
+
+        $tasks = collect($this->invoice->line_items)->map(function ($item){
+
+            if(isset($item->task_id))
+                $item->task_id = $this->decodePrimaryKey($item->task_id);
+
+            if(isset($item->expense_id))
+                $item->expense_id = $this->decodePrimaryKey($item->expense_id);
+
+            return $item;
+
+        });
+
+        $this->assertEquals($tasks->first()->task_id, $this->task->id);
+        $this->assertEquals($tasks->first()->expense_id, $this->expense->id);
+
+        $this->invoice = $this->invoice->service()->linkEntities()->save();
+
+        $this->assertEquals($this->task->fresh()->invoice_id, $temp_invoice_id);
+        $this->assertEquals($this->expense->fresh()->invoice_id, $temp_invoice_id);
+    }
+}
diff --git a/tests/MockAccountData.php b/tests/MockAccountData.php
index df2a56a3cf3d..6d6461e1e7d3 100644
--- a/tests/MockAccountData.php
+++ b/tests/MockAccountData.php
@@ -570,6 +570,8 @@ trait MockAccountData
         $item = InvoiceItemFactory::create();
         $item->quantity = 1;
         $item->cost = 10;
+        $item->task_id = $this->encodePrimaryKey($this->task->id);
+        $item->expense_id = $this->encodePrimaryKey($this->expense->id);
 
         $line_items[] = $item;