diff --git a/app/Models/Subscription.php b/app/Models/Subscription.php
index 9fd27cbfee2f..132b57cfe6e3 100644
--- a/app/Models/Subscription.php
+++ b/app/Models/Subscription.php
@@ -123,6 +123,8 @@ class Subscription extends BaseModel
         'updated_at' => 'timestamp',
         'created_at' => 'timestamp',
         'deleted_at' => 'timestamp',
+        'trial_enabled' => 'boolean',
+        'allow_plan_changes' => 'boolean',
     ];
 
     protected $with = [
diff --git a/app/Services/Subscription/ProRata.php b/app/Services/Subscription/ProRata.php
index 9dfc355ba2f0..6a822c4d11ed 100644
--- a/app/Services/Subscription/ProRata.php
+++ b/app/Services/Subscription/ProRata.php
@@ -58,29 +58,6 @@ class ProRata extends AbstractService
         return $this;
     }
                 
-    /**
-     * Calculates the number of seconds
-     * of the current interval that has been used.
-     *
-     * @return self
-     */
-    private function checkProRataDuration(): self
-    {
-        
-        $primary_invoice = $this->recurring_invoice
-                                ->invoices()
-                                ->where('is_deleted', 0)
-                                ->where('is_proforma', 0)
-                                ->orderBy('id', 'desc')
-                                ->first();
-
-        $duration = Carbon::parse($primary_invoice->date)->startOfDay()->diffInSeconds(now());
-
-        $this->setProRataDuration(max(0, $duration));
-
-        return $this;
-    }
-
     private function calculateProRataRatio(): self
     {
         if($this->pro_rata_duration < $this->subscription_interval_duration)
@@ -92,9 +69,7 @@ class ProRata extends AbstractService
 
     private function calculateSubscriptionIntervalDuration(): self
     {
-        if($this->getIsTrial())
-            return $this->setSubscriptionIntervalDuration(0);
-
+       
         $primary_invoice = $this->recurring_invoice
                                 ->invoices()
                                 ->where('is_deleted', 0)
@@ -113,52 +88,6 @@ class ProRata extends AbstractService
         return $this;
     }
 
-    /**
-     * Determines if this subscription
-     * is eligible for a refund.
-     *
-     * @return self
-     */
-    private function checkRefundPeriod(): self
-    {
-        if(!$this->recurring_invoice->subscription->refund_period || $this->recurring_invoice->subscription->refund_period === 0)
-            return $this->setRefundable(false);
-    
-        $primary_invoice = $this->recurring_invoice
-                                ->invoices()
-                                ->where('is_deleted', 0)
-                                ->where('is_proforma', 0)
-                                ->orderBy('id', 'desc')
-                                ->first();
-
-        if($primary_invoice &&
-        $primary_invoice->status_id == Invoice::STATUS_PAID &&
-        Carbon::parse($primary_invoice->date)->addSeconds($this->recurring_invoice->subscription->refund_period)->lte(now()->startOfDay()->addSeconds($primary_invoice->client->timezone_offset()))
-        ){
-            return $this->setRefundable(true);
-        }
-
-        return $this->setRefundable(false);
-
-    }
-
-    /**
-     * Gathers any unpaid invoices for this subscription.
-     *
-     * @return self
-     */
-    private function checkUnpaidInvoices(): self
-    {
-        $this->unpaid_invoices = $this->recurring_invoice
-                                ->invoices()
-                                ->where('is_deleted', 0)
-                                ->where('is_proforma', 0)
-                                ->whereIn('status_id', [Invoice::STATUS_SENT, Invoice::STATUS_PARTIAL])
-                                ->where('balance', '>', 0)
-                                ->get();
-
-        return $this;
-    }
     
     private function setProRataRatio(int $ratio): self
     {
@@ -192,117 +121,6 @@ class ProRata extends AbstractService
         return $this;
     }
     
-    /**
-     * setRefundable
-     *
-     * @param  bool $refundable
-     * @return self
-     */
-    private function setRefundable(bool $refundable): self
-    {
-        $this->refundable = $refundable;
-
-        return $this;
-    }
-
-    /**
-     * Determines if this users is in their trial period
-     *
-     * @return self
-     */
-    private function isInTrialPeriod(): self
-    {
-
-        if(!$this->recurring_invoice->subscription->trial_enabled) 
-            return $this->setIsTrial(false);
-            
-        $primary_invoice = $this->recurring_invoice
-                            ->invoices()
-                            ->where('is_deleted', 0)
-                            ->where('is_proforma', 0)
-                            ->orderBy('id', 'asc')
-                            ->first();
-    
-        if($primary_invoice && Carbon::parse($primary_invoice->date)->addSeconds($this->recurring_invoice->subscription->trial_duration)->lte(now()->startOfDay()->addSeconds($primary_invoice->client->timezone_offset())))
-            return $this->setIsTrial(true);
-
-        $this->setIsTrial(false);
-
-        return $this;
-    }
-
-    /**
-     * Sets the is_trial flag
-     *
-     * @param  bool $is_trial
-     * @return self
-     */
-    private function setIsTrial(bool $is_trial): self
-    {
-        $this->is_trial = $is_trial;
-
-        return $this;
-    }
- 
         
-    /**
-     * Getter for unpaid invoices
-     *
-     * @return \Illuminate\Database\Eloquent\Collection | null
-     */
-    public function getUnpaidInvoices(): ?\Illuminate\Database\Eloquent\Collection
-    {
-        return $this->unpaid_invoices;
-    }
 
-    /**
-     * Gets the is_trial flag
-     *
-     * @return bool
-     */
-    public function getIsTrial(): bool
-    {
-        return $this->is_trial;
-    }
-    
-    /**
-     * Getter for refundable flag
-     *
-     * @return bool
-     */
-    public function getRefundable(): bool
-    {
-        return $this->refundable;
-    }
-    
-    /**
-     * The number of seconds used in the current duration
-     *
-     * @return int
-     */
-    public function getProRataDuration(): int
-    {
-        return $this->pro_rata_duration;
-    }
-    
-    /**
-     * The total number of seconds in this subscription interval
-     *
-     * @return int
-     */
-    public function getSubscriptionIntervalDuration(): int
-    {
-        return $this->subscription_interval_duration;
-    }
-
-        
-    /**
-     * Returns the pro rata ratio to be applied to any credit.
-     *
-     * @return int
-     */
-    public function getProRataRatio(): int
-    {
-        return $this->pro_rata_ratio;
-    }
 }
\ No newline at end of file
diff --git a/app/Services/Subscription/SubscriptionService.php b/app/Services/Subscription/SubscriptionService.php
index d9631b766ce3..0daf9adac60f 100644
--- a/app/Services/Subscription/SubscriptionService.php
+++ b/app/Services/Subscription/SubscriptionService.php
@@ -1352,7 +1352,7 @@ class SubscriptionService
      *
      * @return int Number of days
      */
-    private function getDaysInFrequency(): int
+    public function getDaysInFrequency(): int
     {
         switch ($this->subscription->frequency_id) {
             case RecurringInvoice::FREQUENCY_DAILY:
diff --git a/app/Services/Subscription/SubscriptionStatus.php b/app/Services/Subscription/SubscriptionStatus.php
index e59bb51c8303..3d842675ab31 100644
--- a/app/Services/Subscription/SubscriptionStatus.php
+++ b/app/Services/Subscription/SubscriptionStatus.php
@@ -43,8 +43,15 @@ class SubscriptionStatus extends AbstractService
     {
         //calculate how much used.
 
-        $primary_invoice = $this->recurring_invoice
-                                ->invoices()
+        $subscription_interval_end_date = Carbon::parse($this->recurring_invoice->next_send_date_client);
+        $subscription_interval_start_date = $subscription_interval_end_date->copy()->subDays($this->recurring_invoice->subscription->service()->getDaysInFrequency())->subDay();
+
+        $primary_invoice =Invoice::query()
+                                ->where('company_id', $this->recurring_invoice->company_id)
+                                ->where('client_id', $this->recurring_invoice->client_id)
+                                ->where('recurring_id', $this->recurring_invoice->id)
+                                ->whereIn('status_id', [Invoice::STATUS_PAID])
+                                ->whereBetween('date', [$subscription_interval_start_date, $subscription_interval_end_date])
                                 ->where('is_deleted', 0)
                                 ->where('is_proforma', 0)
                                 ->orderBy('id', 'desc')
@@ -54,12 +61,10 @@ class SubscriptionStatus extends AbstractService
             return 0;
         
         $subscription_start_date = Carbon::parse($primary_invoice->date)->startOfDay();
-        $subscription_interval_end_date = Carbon::parse($this->recurring_invoice->next_send_date_client);
 
-        $seconds_of_subscription_used = $subscription_start_date->diffInDays(now());
-        $total_seconds_in_subscription_interval = $subscription_start_date->diffInDays($subscription_interval_end_date);
+        $days_of_subscription_used = $subscription_start_date->copy()->diffInDays(now());
 
-        return $seconds_of_subscription_used / $total_seconds_in_subscription_interval;
+        return $days_of_subscription_used / $this->recurring_invoice->subscription->service()->getDaysInFrequency();
 
     }
 
@@ -71,11 +76,13 @@ class SubscriptionStatus extends AbstractService
     private function checkInGoodStanding(): self
     {
 
-        $this->is_in_good_standing = $this->recurring_invoice
-                                     ->invoices()
+        $this->is_in_good_standing = Invoice::query()
+                                     ->where('company_id', $this->recurring_invoice->company_id)
+                                     ->where('client_id', $this->recurring_invoice->client_id)
+                                     ->where('recurring_id', $this->recurring_invoice->id)
                                      ->where('is_deleted', 0)
-                                     ->where('is_proform', 0)
-                                     ->whereIn('status_id', [Invoice::STATUS_SENT, Invoice::STATUS_PAID])
+                                     ->where('is_proforma', 0)
+                                     ->whereIn('status_id', [Invoice::STATUS_SENT, Invoice::STATUS_PARTIAL])
                                      ->where('balance', '>', 0)
                                      ->doesntExist();
 
@@ -92,7 +99,7 @@ class SubscriptionStatus extends AbstractService
     {
 
         if(!$this->subscription->trial_enabled)
-            $this->setIsTrial(false);
+            return $this->setIsTrial(false);
 
         $primary_invoice = $this->recurring_invoice
                             ->invoices()
diff --git a/tests/Feature/PaymentLink/PaymentLinkTest.php b/tests/Feature/PaymentLink/PaymentLinkTest.php
new file mode 100644
index 000000000000..185f45099b10
--- /dev/null
+++ b/tests/Feature/PaymentLink/PaymentLinkTest.php
@@ -0,0 +1,253 @@
+<?php
+/**
+ * Invoice Ninja (https://invoiceninja.com).
+ *
+ * @link https://github.com/invoiceninja/invoiceninja source repository
+ *
+ * @copyright Copyright (c) 2021. Invoice Ninja LLC (https://invoiceninja.com)
+ *
+ * @license https://www.elastic.co/licensing/elastic-license
+ */
+
+namespace Tests\Feature;
+
+use Tests\TestCase;
+use App\Models\Invoice;
+use Tests\MockUnitData;
+use App\Models\Subscription;
+use Illuminate\Support\Carbon;
+use App\Helpers\Invoice\ProRata;
+use App\Models\RecurringInvoice;
+use App\Factory\InvoiceItemFactory;
+use App\Helpers\Subscription\SubscriptionCalculator;
+
+/**
+ * @test
+ */
+class PaymentLinkTest extends TestCase
+{
+    use MockUnitData;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->makeTestData();
+    }
+
+    public function testCalcUpgradePrice()
+    {
+        $subscription = Subscription::factory()->create([
+            'company_id' => $this->company->id,
+            'user_id' => $this->user->id,
+            'price' => 10,
+        ]);
+
+        $target = Subscription::factory()->create([
+            'company_id' => $this->company->id,
+            'user_id' => $this->user->id,
+            'price' => 20,
+        ]);
+
+        $recurring_invoice = RecurringInvoice::factory()->create([
+            'line_items' => $this->buildLineItems(),
+            'company_id' => $this->company->id,
+            'user_id' => $this->user->id,
+            'client_id' => $this->client->id,
+            'tax_rate1' => 0,
+            'tax_name1' => '',
+            'tax_rate2' => 0,
+            'tax_name2' => '',
+            'tax_rate3' => 0,
+            'tax_name3' => '',
+            'discount' => 0,
+            'subscription_id' => $subscription->id,
+            'date' => now()->subWeeks(2),
+            'next_send_date_client' => now(),
+        ]);
+
+
+        $invoice = Invoice::factory()->create([
+            'line_items' => $this->buildLineItems(),
+            'company_id' => $this->company->id,
+            'user_id' => $this->user->id,
+            'client_id' => $this->client->id,
+            'tax_rate1' => 0,
+            'tax_name1' => '',
+            'tax_rate2' => 0,
+            'tax_name2' => '',
+            'tax_rate3' => 0,
+            'tax_name3' => '',
+            'discount' => 0,
+            'subscription_id' => $subscription->id,
+            'date' => now()->subWeeks(2),
+            'recurring_id' => $recurring_invoice->id,
+        ]);
+
+        $recurring_invoice = $recurring_invoice->calc()->getInvoice();
+        $invoice = $invoice->calc()->getInvoice();
+        $this->assertEquals(10, $invoice->amount);
+        $invoice->service()->markSent()->save();
+        $this->assertEquals(10, $invoice->amount);
+        $this->assertEquals(10, $invoice->balance);
+        $invoice = $invoice->service()->markPaid()->save();
+        $this->assertEquals(0, $invoice->balance);
+        $this->assertEquals(10, $invoice->paid_to_date);
+
+        $status = $recurring_invoice
+                    ->subscription
+                    ->status($recurring_invoice);
+
+        $this->assertFalse($status->is_trial);
+        $this->assertFalse($status->is_refundable);
+        $this->assertTrue($status->is_in_good_standing);
+
+        $days = $recurring_invoice->subscription->service()->getDaysInFrequency();
+
+        $ratio = (14 / $days);
+
+        $this->assertEquals($ratio, $status->getProRataRatio());
+
+        $price = $target->link_service()->calculateUpgradePriceV2($recurring_invoice, $target);
+
+        $refund = round($invoice->paid_to_date*$ratio,2);
+
+        $this->assertEquals(($target->price - $refund), $price);
+        
+        
+        // $this->assertEquals($target->price-$refund, $upgrade_price);
+
+        // $sub_calculator = new SubscriptionCalculator($target->fresh(), $invoice->fresh());
+
+        // $this->assertFalse($sub_calculator->isPaidUp());
+
+        // $invoice = $invoice->service()->markPaid()->save();
+
+        // $this->assertTrue($sub_calculator->isPaidUp());
+
+        // $this->assertEquals(10, $invoice->amount);
+        // $this->assertEquals(0, $invoice->balance);
+
+        // $pro_rata = new ProRata();
+
+        // $refund = $pro_rata->refund($invoice->amount, Carbon::parse('2021-01-01'), Carbon::parse('2021-01-06'), $subscription->frequency_id);
+
+        // // $this->assertEquals(1.61, $refund);
+
+        // $pro_rata = new ProRata();
+
+        // $upgrade = $pro_rata->charge($target->price, Carbon::parse('2021-01-01'), Carbon::parse('2021-01-06'), $subscription->frequency_id);
+
+        // $this->assertEquals(3.23, $upgrade);
+    }
+
+    // public function testProrataDiscountRatioPercentage()
+    // {
+    //     $subscription = Subscription::factory()->create([
+    //         'company_id' => $this->company->id,
+    //         'user_id' => $this->user->id,
+    //         'price' => 100,
+    //     ]);
+
+    //     $item = InvoiceItemFactory::create();
+    //     $item->quantity = 1;
+
+    //     $item->cost = 100;
+    //     $item->product_key = 'xyz';
+    //     $item->notes = 'test';
+    //     $item->custom_value1 = 'x';
+    //     $item->custom_value2 = 'x';
+    //     $item->custom_value3 = 'x';
+    //     $item->custom_value4 = 'x';
+
+    //     $line_items[] = $item;
+
+    //     $invoice = Invoice::factory()->create([
+    //         'line_items' => $line_items,
+    //         'company_id' => $this->company->id,
+    //         'user_id' => $this->user->id,
+    //         'client_id' => $this->client->id,
+    //         'tax_rate1' => 0,
+    //         'tax_name1' => '',
+    //         'tax_rate2' => 0,
+    //         'tax_name2' => '',
+    //         'tax_rate3' => 0,
+    //         'tax_name3' => '',
+    //         'discount' => 0,
+    //         'subscription_id' => $subscription->id,
+    //         'date' => '2021-01-01',
+    //         'discount' => 10,
+    //         'is_amount_discount' => false,
+    //         'status_id' => 1,
+    //     ]);
+
+    //     $invoice = $invoice->calc()->getInvoice();
+    //     $this->assertEquals(90, $invoice->amount);
+    //     $this->assertEquals(0, $invoice->balance);
+
+    //     $invoice->service()->markSent()->save();
+
+    //     $this->assertEquals(90, $invoice->amount);
+    //     $this->assertEquals(90, $invoice->balance);
+
+
+    //     $ratio = $subscription->service()->calculateDiscountRatio($invoice);
+
+    //     $this->assertEquals(.1, $ratio);
+    // }
+
+    // public function testProrataDiscountRatioAmount()
+    // {
+    //     $subscription = Subscription::factory()->create([
+    //         'company_id' => $this->company->id,
+    //         'user_id' => $this->user->id,
+    //         'price' => 100,
+    //     ]);
+
+    //     $item = InvoiceItemFactory::create();
+    //     $item->quantity = 1;
+
+    //     $item->cost = 100;
+    //     $item->product_key = 'xyz';
+    //     $item->notes = 'test';
+    //     $item->custom_value1 = 'x';
+    //     $item->custom_value2 = 'x';
+    //     $item->custom_value3 = 'x';
+    //     $item->custom_value4 = 'x';
+
+    //     $line_items[] = $item;
+
+    //     $invoice = Invoice::factory()->create([
+    //         'line_items' => $line_items,
+    //         'company_id' => $this->company->id,
+    //         'user_id' => $this->user->id,
+    //         'client_id' => $this->client->id,
+    //         'tax_rate1' => 0,
+    //         'tax_name1' => '',
+    //         'tax_rate2' => 0,
+    //         'tax_name2' => '',
+    //         'tax_rate3' => 0,
+    //         'tax_name3' => '',
+    //         'discount' => 0,
+    //         'subscription_id' => $subscription->id,
+    //         'date' => '2021-01-01',
+    //         'discount' => 20,
+    //         'is_amount_discount' => true,
+    //         'status_id' => 1,
+    //     ]);
+
+    //     $invoice = $invoice->calc()->getInvoice();
+    //     $this->assertEquals(80, $invoice->amount);
+    //     $this->assertEquals(0, $invoice->balance);
+
+    //     $invoice->service()->markSent()->save();
+
+    //     $this->assertEquals(80, $invoice->amount);
+    //     $this->assertEquals(80, $invoice->balance);
+
+
+    //     $ratio = $subscription->service()->calculateDiscountRatio($invoice);
+
+    //     $this->assertEquals(.2, $ratio);
+    // }
+}