diff --git a/app/Http/Requests/User/UpdateUserRequest.php b/app/Http/Requests/User/UpdateUserRequest.php
index 966d8b24d5d3..eda9afb9fc74 100644
--- a/app/Http/Requests/User/UpdateUserRequest.php
+++ b/app/Http/Requests/User/UpdateUserRequest.php
@@ -45,9 +45,6 @@ class UpdateUserRequest extends Request
     {
         $input = $this->all();
 
-        // if (isset($input['company_user']) && ! auth()->user()->isAdmin()) {
-        //     unset($input['company_user']);
-        // }
 
         $this->replace($input);
     }
diff --git a/app/Http/ValidationRules/UniqueUserRule.php b/app/Http/ValidationRules/UniqueUserRule.php
index e6eb7be90782..b9bca3a2e5bc 100644
--- a/app/Http/ValidationRules/UniqueUserRule.php
+++ b/app/Http/ValidationRules/UniqueUserRule.php
@@ -60,12 +60,6 @@ class UniqueUserRule implements Rule
      */
     private function checkIfEmailExists($email) : bool
     {
-        $current_db = config('database.default');
-
-        $result =  MultiDB::checkUserEmailExists($email);
-
-        MultiDB::setDb($current_db);
-        
-        return $result;
+        return MultiDB::checkUserEmailExists($email);
     }
 }
diff --git a/app/Http/ValidationRules/User/AttachableUser.php b/app/Http/ValidationRules/User/AttachableUser.php
index 226d67b702cb..db7cec97a3e3 100644
--- a/app/Http/ValidationRules/User/AttachableUser.php
+++ b/app/Http/ValidationRules/User/AttachableUser.php
@@ -20,6 +20,7 @@ use Illuminate\Contracts\Validation\Rule;
  */
 class AttachableUser implements Rule
 {
+    public $message;
 
     public function __construct()
     {
@@ -39,7 +40,7 @@ class AttachableUser implements Rule
      */
     public function message()
     {
-        return "Cannot add the same user to the same company";
+        return $this->message;
     }
 
     /**
@@ -63,9 +64,16 @@ class AttachableUser implements Rule
                                     ->where('company_id', auth()->user()->company()->id)
                                     ->exists();
 
-        if($user_already_attached)
+        //If the user is already attached or isn't link to this account - return false
+        if($user_already_attached) {
+            $this->message = ctrans('texts.user_duplicate_error');
             return false;
+        } 
 
+        if($user->account_id != auth()->user()->account_id){
+            $this->message = ctrans('texts.user_cross_linked_error');
+            return false;            
+        }
 
         return true;
     }
diff --git a/app/Http/ValidationRules/ValidUserForCompany.php b/app/Http/ValidationRules/ValidUserForCompany.php
index cb3825704606..967ca56591d7 100644
--- a/app/Http/ValidationRules/ValidUserForCompany.php
+++ b/app/Http/ValidationRules/ValidUserForCompany.php
@@ -26,14 +26,7 @@ class ValidUserForCompany implements Rule
      */
     public function passes($attribute, $value)
     {
-        $current_db = config('database.default');
-
-        $result = MultiDB::checkUserAndCompanyCoExist($value, auth()->user()->company()->company_key, auth()->user()->company()->id);
-
-
-        MultiDB::setDb($current_db);
-
-        return $result;
+        return MultiDB::checkUserAndCompanyCoExist($value, auth()->user()->company()->company_key, auth()->user()->company()->id);
     }
 
     /**
diff --git a/app/Jobs/Util/Import.php b/app/Jobs/Util/Import.php
index 074716d9468e..f21a9817840b 100644
--- a/app/Jobs/Util/Import.php
+++ b/app/Jobs/Util/Import.php
@@ -423,7 +423,8 @@ class Import implements ShouldQueue
         $rules = [
             '*.first_name' => ['string'],
             '*.last_name' => ['string'],
-            '*.email' => ['distinct'],
+            //'*.email' => ['distinct'],
+            '*.email' => ['distinct', 'email', new ValidUserForCompany(), new AttachableUser()],
         ];
 
         // if (config('ninja.db.multi_db_enabled')) {
diff --git a/app/Libraries/MultiDB.php b/app/Libraries/MultiDB.php
index 83519d6c46e4..51afc34ae331 100644
--- a/app/Libraries/MultiDB.php
+++ b/app/Libraries/MultiDB.php
@@ -106,8 +106,8 @@ class MultiDB
         $current_db = config('database.default');  
 
         foreach (self::$dbs as $db) {
-            if (User::on($db)->where(['email' => $email])->get()->count() >= 1) { // if user already exists, validation will fail
-                if (Company::on($db)->where(['company_key' => $company_key])->get()->count() >= 1) {
+            if (User::on($db)->where(['email' => $email])->exists()) { 
+                if (Company::on($db)->where(['company_key' => $company_key])->exists()) {
                     self::setDb($current_db);
                     return true;
                 } else {
diff --git a/app/Services/Invoice/UpdateReminder.php b/app/Services/Invoice/UpdateReminder.php
index c9a0078e6d7a..60faac74f108 100644
--- a/app/Services/Invoice/UpdateReminder.php
+++ b/app/Services/Invoice/UpdateReminder.php
@@ -38,7 +38,7 @@ class UpdateReminder extends AbstractService
             $this->invoice->next_send_date = null;
             $this->invoice->save();
 
-            return; //exit early
+            return $this->invoice; //exit early
         }
 
         $date_collection = collect();
diff --git a/resources/lang/en/texts.php b/resources/lang/en/texts.php
index 09ecf7a16aee..e329553bd1f9 100644
--- a/resources/lang/en/texts.php
+++ b/resources/lang/en/texts.php
@@ -4252,6 +4252,8 @@ $LANG = array(
     'contact_details' => 'Contact Details',
     'download_backup_subject' => 'Your company backup is ready for download',
     'account_passwordless_login' => 'Account passwordless login',
+    'user_duplicate_error' => 'Cannot add the same user to the same company',
+    'user_cross_linked_error' => 'User exists but cannot be crossed linked to multiple accounts',
 );
 
 return $LANG;
diff --git a/tests/Integration/CheckRemindersTest.php b/tests/Integration/CheckRemindersTest.php
index f58cc42339fa..78c5ab89f483 100644
--- a/tests/Integration/CheckRemindersTest.php
+++ b/tests/Integration/CheckRemindersTest.php
@@ -25,7 +25,6 @@ class CheckRemindersTest extends TestCase
 {
     use MockAccountData;
     use DatabaseTransactions;
-    use MakesReminders;
 
     public function setUp() :void
     {
diff --git a/tests/MockAccountData.php b/tests/MockAccountData.php
index f20b0a4737fa..ad5225270ddc 100644
--- a/tests/MockAccountData.php
+++ b/tests/MockAccountData.php
@@ -192,10 +192,10 @@ trait MockAccountData
 
         if (! $user) {
             $user = User::factory()->create([
-                                'account_id' => $this->account->id,
-                                'confirmation_code' => $this->createDbHash(config('database.default')),
-                                'email' => 'user@example.com',
-                            ]);
+                'account_id' => $this->account->id,
+                'confirmation_code' => $this->createDbHash(config('database.default')),
+                'email' => 'user@example.com',
+            ]);
         }
 
         $user->password = Hash::make('ALongAndBriliantPassword');