diff --git a/src/Campaigns/Actions/ConvertQueryDataToCampaign.php b/src/Campaigns/Actions/ConvertQueryDataToCampaign.php
index 4c13e2fd78..a064898b87 100644
--- a/src/Campaigns/Actions/ConvertQueryDataToCampaign.php
+++ b/src/Campaigns/Actions/ConvertQueryDataToCampaign.php
@@ -20,6 +20,7 @@ public function __invoke(object $queryObject): Campaign
     {
         return new Campaign([
             'id' => (int)$queryObject->id,
+            'defaultFormId' => (int)$queryObject->defaultFormId,
             'type' => new CampaignType($queryObject->type),
             'enableCampaignPage' => (bool)$queryObject->enableCampaignPage,
             'title' => $queryObject->title,
diff --git a/src/Campaigns/Actions/LoadCampaignDetailsAssets.php b/src/Campaigns/Actions/LoadCampaignDetailsAssets.php
index 2f0e0301c7..7a815c5918 100644
--- a/src/Campaigns/Actions/LoadCampaignDetailsAssets.php
+++ b/src/Campaigns/Actions/LoadCampaignDetailsAssets.php
@@ -4,7 +4,6 @@
 
 use Give\Campaigns\Models\Campaign;
 use Give\Framework\Support\Facades\Scripts\ScriptAsset;
-use Give\Helpers\Form\Utils;
 
 /**
  * @unreleased
@@ -34,13 +33,12 @@ public function __invoke()
         );
 
         $defaultForm = $campaign->defaultForm();
-        $defaultFormTitle = Utils::isV3Form($defaultForm->id) ? $defaultForm->settings->formTitle : $defaultForm->title;
         wp_localize_script($handleName, 'GiveCampaignDetails',
             [
                 'adminUrl' => admin_url(),
                 'currency' => give_get_currency(),
                 'isRecurringEnabled' => defined('GIVE_RECURRING_VERSION') ? GIVE_RECURRING_VERSION : null,
-                'defaultForm' => $defaultFormTitle,
+                'defaultForm' => $defaultForm->title,
             ]
         );
 
diff --git a/src/Campaigns/Controllers/CampaignRequestController.php b/src/Campaigns/Controllers/CampaignRequestController.php
index 3b7a7ce371..357b2f3fa6 100644
--- a/src/Campaigns/Controllers/CampaignRequestController.php
+++ b/src/Campaigns/Controllers/CampaignRequestController.php
@@ -130,8 +130,7 @@ public function updateCampaign(WP_REST_Request $request)
                     $campaign->goalType = new CampaignGoalType($value);
                     break;
                 case 'defaultFormId':
-                    give(CampaignRepository::class)->updateDefaultCampaignForm($campaign,
-                        $request->get_param('defaultFormId'));
+                    give(CampaignRepository::class)->updateDefaultCampaignForm($campaign, $request->get_param('defaultFormId'));
                     break;
                 default:
                     if ($campaign->hasProperty($key)) {
@@ -147,6 +146,21 @@ public function updateCampaign(WP_REST_Request $request)
         return new WP_REST_Response($campaign->toArray());
     }
 
+    /**
+     * @unreleased
+     *
+     * @throws Exception
+     */
+    public function mergeCampaigns(WP_REST_Request $request): WP_REST_Response
+    {
+        $destinationCampaign = Campaign::find($request->get_param('id'));
+        $campaignsToMerge = Campaign::query()->whereIn('id', $request->get_param('campaignsToMergeIds'))->getAll();
+
+        $campaignsMerged = $destinationCampaign->merge(...$campaignsToMerge);
+
+        return new WP_REST_Response($campaignsMerged);
+    }
+
 
     /**
      * @unreleased
diff --git a/src/Campaigns/Factories/CampaignFactory.php b/src/Campaigns/Factories/CampaignFactory.php
index 5f467c0485..1cc64f9510 100644
--- a/src/Campaigns/Factories/CampaignFactory.php
+++ b/src/Campaigns/Factories/CampaignFactory.php
@@ -23,6 +23,7 @@ public function definition(): array
         return [
             'type' => CampaignType::CORE(),
             'enableCampaignPage' => true,
+            'defaultFormId' => 1,
             'title' => __('GiveWP Campaign', 'give'),
             'shortDescription' => __('Campaign short description', 'give'),
             'longDescription' => __('Campaign long description', 'give'),
diff --git a/src/Campaigns/Migrations/MigrateFormsToCampaignForms.php b/src/Campaigns/Migrations/MigrateFormsToCampaignForms.php
index ce4e42f149..07ce2f3b1b 100644
--- a/src/Campaigns/Migrations/MigrateFormsToCampaignForms.php
+++ b/src/Campaigns/Migrations/MigrateFormsToCampaignForms.php
@@ -116,6 +116,7 @@ public function createCampaignForForm($formData): void
 
         DB::table('give_campaigns')
             ->insert([
+                'form_id' => $formId,
                 'campaign_type' => 'core',
                 'campaign_title' => $formTitle,
                 'status' => $this->mapFormToCampaignStatus($formStatus),
@@ -134,7 +135,7 @@ public function createCampaignForForm($formData): void
 
         $campaignId = DB::last_insert_id();
 
-        $this->addCampaignFormRelationship($formId, $campaignId, true);
+        $this->addCampaignFormRelationship($formId, $campaignId);
     }
 
     /**
@@ -142,19 +143,18 @@ public function createCampaignForForm($formData): void
      */
     protected function addUpgradedFormToCampaign($data): void
     {
-        $this->addCampaignFormRelationship($data->migratedFormId, $data->campaignId, false);
+        $this->addCampaignFormRelationship($data->migratedFormId, $data->campaignId);
     }
 
     /**
      * @unreleased
      */
-    protected function addCampaignFormRelationship($formId, $campaignId, $isDefault)
+    protected function addCampaignFormRelationship($formId, $campaignId)
     {
         DB::table('give_campaign_forms')
             ->insert([
                 'form_id' => $formId,
-                'campaign_id' => $campaignId,
-                'is_default' => $isDefault,
+                'campaign_id' => $campaignId
             ]);
     }
 
diff --git a/src/Campaigns/Migrations/RevenueTable/AddCampaignID.php b/src/Campaigns/Migrations/RevenueTable/AddCampaignID.php
index 92101e7c42..a53d7c5586 100644
--- a/src/Campaigns/Migrations/RevenueTable/AddCampaignID.php
+++ b/src/Campaigns/Migrations/RevenueTable/AddCampaignID.php
@@ -2,7 +2,7 @@
 
 namespace Give\Campaigns\Migrations\RevenueTable;
 
-use Give\Framework\Database\Exceptions\DatabaseQueryException;
+use Give\Framework\Database\DB;
 use Give\Framework\Migrations\Contracts\Migration;
 use Give\Framework\Migrations\Exceptions\DatabaseMigrationException;
 
@@ -41,19 +41,11 @@ public static function timestamp(): string
      */
     public function run()
     {
-        global $wpdb;
+        $table = DB::prefix('give_revenue');
+        $columnAdded = maybe_add_column($table, 'campaign_id', "ALTER TABLE $table ADD COLUMN campaign_id INT UNSIGNED NULL");
 
-        $table = $wpdb->give_revenue;
-
-        $sql = "
-            ALTER TABLE $table
-            ADD COLUMN campaign_id INT UNSIGNED NOT NULL DEFAULT '0'
-        ";
-
-        try {
-            $wpdb->query($sql);
-        } catch (DatabaseQueryException $exception) {
-            throw new DatabaseMigrationException("An error occurred while updating the $table table", 0, $exception);
+        if ( ! $columnAdded) {
+            throw new DatabaseMigrationException("An error occurred while updating the $table table");
         }
     }
 }
diff --git a/src/Campaigns/Migrations/Tables/CreateCampaignFormsTable.php b/src/Campaigns/Migrations/Tables/CreateCampaignFormsTable.php
index 92e58b6c57..49c32034c2 100644
--- a/src/Campaigns/Migrations/Tables/CreateCampaignFormsTable.php
+++ b/src/Campaigns/Migrations/Tables/CreateCampaignFormsTable.php
@@ -51,7 +51,6 @@ public function run(): void
         $sql = "CREATE TABLE $table (
             campaign_id INT UNSIGNED NOT NULL,
             form_id INT UNSIGNED NOT NULL,
-            is_default BOOLEAN NOT NULL DEFAULT 0,
             KEY form_id (form_id),
             KEY campaign_id (campaign_id),
             PRIMARY KEY (campaign_id, form_id)
diff --git a/src/Campaigns/Models/Campaign.php b/src/Campaigns/Models/Campaign.php
index c269c19843..23d086d901 100644
--- a/src/Campaigns/Models/Campaign.php
+++ b/src/Campaigns/Models/Campaign.php
@@ -12,8 +12,8 @@
 use Give\Campaigns\ValueObjects\CampaignGoalType;
 use Give\Campaigns\ValueObjects\CampaignStatus;
 use Give\Campaigns\ValueObjects\CampaignType;
-use Give\DonationForms\Models\DonationForm;
-use Give\DonationForms\V2\Models\DonationForm as LegacyDonationForm;
+use Give\DonationForms\V2\Models\DonationForm;
+use Give\DonationForms\V2\Repositories\DonationFormsRepository;
 use Give\Framework\Exceptions\Primitives\InvalidArgumentException;
 use Give\Framework\Models\Contracts\ModelCrud;
 use Give\Framework\Models\Contracts\ModelHasFactory;
@@ -25,6 +25,7 @@
  * @unreleased
  *
  * @property int              $id
+ * @property int              $defaultFormId
  * @property CampaignType     $type
  * @property bool $enableCampaignPage
  * @property string           $title
@@ -49,6 +50,7 @@ class Campaign extends Model implements ModelCrud, ModelHasFactory
      */
     protected $properties = [
         'id' => 'int',
+        'defaultFormId' => 'int',
         'type' => CampaignType::class,
         'enableCampaignPage' => ['bool', true],
         'title' => 'string',
@@ -68,22 +70,10 @@ class Campaign extends Model implements ModelCrud, ModelHasFactory
 
     /**
      * @unreleased
-     *
-     * @return DonationForm | LegacyDonationForm
      */
-    public function defaultForm()
+    public function defaultForm(): ?DonationForm
     {
-        $defaultForm = $this->forms()
-            ->where('campaign_forms.is_default', true)
-            ->get();
-
-        if (is_null($defaultForm)) {
-            $defaultForm = $this->legacyForms()
-                ->where('campaign_forms.is_default', true)
-                ->get();
-        }
-
-        return $defaultForm;
+        return give(DonationFormsRepository::class)->getById($this->defaultFormId);
     }
 
     /**
@@ -93,21 +83,11 @@ public function forms(): ModelQueryBuilder
     {
         return DonationForm::query()
             ->join(function (JoinQueryBuilder $builder) {
-                $builder->leftJoin('give_campaign_forms', 'campaign_forms')
-                    ->on('campaign_forms.form_id', 'forms.id');
-            })->where('campaign_forms.campaign_id', $this->id);
-    }
-
-    /**
-     * @unreleased
-     */
-    public function legacyForms(): ModelQueryBuilder
-    {
-        return LegacyDonationForm::query()
-            ->join(function (JoinQueryBuilder $builder) {
-                $builder->leftJoin('give_campaign_forms', 'campaign_forms')
+                $builder
+                    ->leftJoin('give_campaign_forms', 'campaign_forms')
                     ->on('campaign_forms.form_id', 'id');
-            })->where('campaign_forms.campaign_id', $this->id);
+            })
+            ->where('campaign_forms.campaign_id', $this->id);
     }
 
     /**
diff --git a/src/Campaigns/Repositories/CampaignRepository.php b/src/Campaigns/Repositories/CampaignRepository.php
index d0be320e8b..7b387e5089 100644
--- a/src/Campaigns/Repositories/CampaignRepository.php
+++ b/src/Campaigns/Repositories/CampaignRepository.php
@@ -44,13 +44,13 @@ public function getById(int $id)
     /**
      * @unreleased
      *
-     * Get Campaign by Form ID
+     * Get Campaign by Form ID using a lookup table
      */
     public function getByFormId(int $formId)
     {
         return $this->prepareQuery()
-            ->leftJoin('give_campaign_forms', 'campaigns.id', 'forms.campaign_id', 'forms')
-            ->where('forms.form_id', $formId)
+            ->leftJoin('give_campaign_forms', 'campaigns.id', 'campaignForms.campaign_id', 'campaignForms')
+            ->where('campaignForms.form_id', $formId)
             ->get();
     }
 
@@ -170,24 +170,21 @@ public function addCampaignForm(Campaign $campaign, int $donationFormId, bool $i
         DB::query('START TRANSACTION');
 
         try {
-            // Make sure we'll have only one default form
             if ($isDefault) {
-                DB::table('give_campaign_forms')
-                    ->where('campaign_id', $campaign->id)
+                DB::table('give_campaigns')
+                    ->where('id', $campaign->id)
                     ->update([
-                        'is_default' => false,
+                        'form_id' => $donationFormId,
                     ]);
+
+                $campaign->defaultFormId = $donationFormId;
             }
 
-            $table = DB::prefix('give_campaign_forms');
-            DB::query(
-                DB::prepare("INSERT INTO {$table} (form_id, campaign_id, is_default ) VALUES (%d, %d, %d)",
-                    [
-                        $donationFormId,
-                        $campaign->id,
-                        $isDefault,
-                    ])
-            );
+            DB::table('give_campaign_forms')
+                ->insert([
+                    'form_id' => $donationFormId,
+                    'campaign_id' => $campaign->id,
+                ]);
         } catch (Exception $exception) {
             DB::query('ROLLBACK');
 
@@ -213,13 +210,13 @@ public function updateDefaultCampaignForm(Campaign $campaign, int $donationFormI
         DB::query('START TRANSACTION');
 
         try {
-            DB::query(
-                DB::prepare('UPDATE ' . DB::prefix('give_campaign_forms') . ' SET is_default = IF(form_id = %d, 1, 0) WHERE campaign_id = %d',
-                    [
-                        $donationFormId,
-                        $campaign->id,
-                    ])
-            );
+            DB::table('give_campaigns')
+                ->where('id', $campaign->id)
+                ->update([
+                    'form_id' => $donationFormId
+                ]);
+
+            $campaign->defaultFormId = $donationFormId;
         } catch (Exception $exception) {
             DB::query('ROLLBACK');
 
@@ -295,7 +292,7 @@ public function mergeCampaigns(Campaign $destinationCampaign, Campaign ...$campa
 
             // Migrate forms from campaigns to merge to the destination campaign
             DB::query(
-                DB::prepare("UPDATE " . DB::prefix('give_campaign_forms') . " SET is_default = 0, campaign_id = %d WHERE campaign_id IN ($campaignsToMergeIdsString)",
+                DB::prepare("UPDATE " . DB::prefix('give_campaign_forms') . " SET campaign_id = %d WHERE campaign_id IN ($campaignsToMergeIdsString)",
                     [
                         $destinationCampaign->id,
                     ])
@@ -345,6 +342,7 @@ public function prepareQuery(): ModelQueryBuilder
         return $builder->from('give_campaigns', 'campaigns')
             ->select(
                 'id',
+                ['campaigns.form_id', 'defaultFormId'], // Prefix the `form_id` column to avoid conflicts with the `give_campaign_forms` table.
                 ['campaign_type', 'type'],
                 ['enable_campaign_page', 'enableCampaignPage'],
                 ['campaign_title', 'title'],
diff --git a/src/Campaigns/Routes/MergeCampaigns.php b/src/Campaigns/Routes/MergeCampaigns.php
deleted file mode 100644
index 1999fa3638..0000000000
--- a/src/Campaigns/Routes/MergeCampaigns.php
+++ /dev/null
@@ -1,65 +0,0 @@
-<?php
-
-namespace Give\Campaigns\Routes;
-
-use Exception;
-use Give\API\RestRoute;
-use Give\Campaigns\Models\Campaign;
-use Give\Campaigns\ValueObjects\CampaignRoute;
-use WP_REST_Request;
-use WP_REST_Response;
-use WP_REST_Server;
-
-/**
- * @unreleased
- */
-class MergeCampaigns implements RestRoute
-{
-    /**
-     * @unreleased
-     */
-    public function registerRoute()
-    {
-        register_rest_route(
-            CampaignRoute::NAMESPACE,
-            CampaignRoute::CAMPAIGN . '/merge',
-            [
-                [
-                    'methods' => WP_REST_Server::EDITABLE,
-                    'callback' => [$this, 'handleRequest'],
-                    'permission_callback' => function () {
-                        return current_user_can('manage_options');
-                    },
-                ],
-                'args' => [
-                    'id' => [
-                        'type' => 'integer',
-                        'required' => true,
-                    ],
-                    'campaignsToMergeIds' => [
-                        'type' => 'array',
-                        'required' => true,
-                        'items' => [
-                            'type' => 'integer',
-                        ],
-                    ],
-                ],
-            ]
-        );
-    }
-
-    /**
-     * @unreleased
-     *
-     * @throws Exception
-     */
-    public function handleRequest(WP_REST_Request $request): WP_REST_Response
-    {
-        $destinationCampaign = Campaign::find($request->get_param('id'));
-        $campaignsToMerge = Campaign::query()->whereIn('id', $request->get_param('campaignsToMergeIds'))->getAll();
-
-        $campaignsMerged = $destinationCampaign->merge(...$campaignsToMerge);
-
-        return new WP_REST_Response($campaignsMerged);
-    }
-}
diff --git a/src/Campaigns/Routes/RegisterCampaignRoutes.php b/src/Campaigns/Routes/RegisterCampaignRoutes.php
index d6b5e0ad25..9d7d9b71ec 100644
--- a/src/Campaigns/Routes/RegisterCampaignRoutes.php
+++ b/src/Campaigns/Routes/RegisterCampaignRoutes.php
@@ -35,6 +35,7 @@ public function __invoke()
         $this->registerGetCampaign();
         $this->registerUpdateCampaign();
         $this->registerGetCampaigns();
+        $this->registerMergeCampaigns();
         $this->registerCreateCampaign();
     }
 
@@ -130,6 +131,44 @@ public function registerUpdateCampaign()
     }
 
 
+    /**
+     * Update Campaign route
+     *
+     * @unreleased
+     */
+    public function registerMergeCampaigns()
+    {
+        register_rest_route(
+            CampaignRoute::NAMESPACE,
+            CampaignRoute::CAMPAIGN . '/merge',
+            [
+                [
+                    'methods' => WP_REST_Server::EDITABLE,
+                    'callback' => function (WP_REST_Request $request) {
+                        return $this->campaignRequestController->mergeCampaigns($request);
+                    },
+                    'permission_callback' => function () {
+                        return current_user_can('manage_options');
+                    },
+                ],
+                'args' => [
+                    'id' => [
+                        'type' => 'integer',
+                        'required' => true,
+                    ],
+                    'campaignsToMergeIds' => [
+                        'type' => 'array',
+                        'required' => true,
+                        'items' => [
+                            'type' => 'integer',
+                        ],
+                    ],
+                ],
+            ]
+        );
+    }
+
+
     /**
      * Create Campaign route
      *
diff --git a/src/Campaigns/ServiceProvider.php b/src/Campaigns/ServiceProvider.php
index e8ec820d2c..012be96503 100644
--- a/src/Campaigns/ServiceProvider.php
+++ b/src/Campaigns/ServiceProvider.php
@@ -57,7 +57,6 @@ private function registerRoutes()
         Hooks::addAction('rest_api_init', Routes\DeleteCampaignListTable::class, 'registerRoute');
         Hooks::addAction('rest_api_init', Routes\GetCampaignStatistics::class, 'registerRoute');
         Hooks::addAction('rest_api_init', Routes\GetCampaignRevenue::class, 'registerRoute');
-        Hooks::addAction('rest_api_init', Routes\MergeCampaigns::class, 'registerRoute');
     }
 
     /**
diff --git a/tests/Unit/Campaigns/Migrations/MigrateFormsToCampaignFormsTest.php b/tests/Unit/Campaigns/Migrations/MigrateFormsToCampaignFormsTest.php
index b763b7653b..c74e5e9857 100644
--- a/tests/Unit/Campaigns/Migrations/MigrateFormsToCampaignFormsTest.php
+++ b/tests/Unit/Campaigns/Migrations/MigrateFormsToCampaignFormsTest.php
@@ -80,9 +80,9 @@ public function testMigratedFormsAreDefault()
         $migration = new MigrateFormsToCampaignForms();
         $migration->run();
 
-        $relationship = DB::table('give_campaign_forms')->where('form_id', $form->id)->get();
+        $campaign = Campaign::findByFormId($form->id);
 
-        $this->assertEquals(1, $relationship->is_default);
+        $this->assertEquals($form->id, $campaign->defaultFormId);
     }
 
     /**
@@ -99,8 +99,8 @@ public function testUpgradedFormsAreNotDefault()
         $migration = new MigrateFormsToCampaignForms();
         $migration->run();
 
-        $relationship = DB::table('give_campaign_forms')->where('form_id', $form1->id)->get();
+        $campaign = Campaign::findByFormId($form2->id);
 
-        $this->assertEquals(0, $relationship->is_default);
+        $this->assertNotEquals($form1->id, $campaign->defaultFormId);
     }
 }
diff --git a/tests/Unit/Campaigns/Models/CampaignModelTest.php b/tests/Unit/Campaigns/Models/CampaignModelTest.php
index afd868895f..239612b666 100644
--- a/tests/Unit/Campaigns/Models/CampaignModelTest.php
+++ b/tests/Unit/Campaigns/Models/CampaignModelTest.php
@@ -56,6 +56,6 @@ public function testCampaignHasDefaultForm()
         $newDefaultForm = DonationForm::factory()->create();
         give(CampaignRepository::class)->addCampaignForm($campaign, $newDefaultForm->id, true);
 
-        $this->assertEquals($newDefaultForm->id, $campaign->defaultForm()->id);
+        $this->assertEquals($newDefaultForm->id, $campaign->defaultFormId);
     }
 }
diff --git a/tests/Unit/Campaigns/Repositories/CampaignRepositoryTest.php b/tests/Unit/Campaigns/Repositories/CampaignRepositoryTest.php
index ea8c39207a..19f9bcb649 100644
--- a/tests/Unit/Campaigns/Repositories/CampaignRepositoryTest.php
+++ b/tests/Unit/Campaigns/Repositories/CampaignRepositoryTest.php
@@ -428,10 +428,6 @@ public function testMergeCampaignsShouldKeepDefaultFormFromDestinationCampaign()
         //Re-fetch
         $destinationCampaign = Campaign::find($destinationCampaign->id);
 
-        $countDefaultForm = $destinationCampaign->forms()
-            ->where('campaign_forms.is_default', true)->count();
-
-        $this->assertEquals(1, $countDefaultForm);
         $this->assertEquals($defaultFormBeforeMerge->id, $destinationCampaign->defaultForm()->id);
     }
 }