[16.x] Flexible Billing Support for Laravel Cashier

config/cashier.php

@@ -124,4 +124,19 @@
 
     'logger' => env('CASHIER_LOGGER'),
 
+    /*
+    |--------------------------------------------------------------------------
+    | Default Billing Mode
+    |--------------------------------------------------------------------------
+    |
+    | This setting defines the default billing mode for new subscriptions.
+    | The billing mode can be either "classic" (default) or "flexible".
+    | Flexible mode enables more flexible subscription behavior including
+    | improved prorations, consolidated invoicing, and mixed intervals.
+    | Requires Stripe API version 2025-06-30.basil or later.
+    |
+    */
+
+    'default_billing_mode' => env('CASHIER_DEFAULT_BILLING_MODE', 'classic'),
+
 ];

database/migrations/2019_05_03_000002_create_subscription_schedules_table.php

@@ -0,0 +1,39 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('subscription_schedules', function (Blueprint $table) {
+            $table->id();
+            $table->unsignedBigInteger('user_id');
+            $table->string('stripe_id')->unique();
+            $table->string('stripe_status');
+            $table->string('subscription_id')->nullable();
+            $table->timestamp('current_phase_started_at')->nullable();
+            $table->timestamp('current_phase_ends_at')->nullable();
+            $table->timestamp('canceled_at')->nullable();
+            $table->timestamp('completed_at')->nullable();
+            $table->timestamp('released_at')->nullable();
+            $table->json('metadata')->nullable();
+            $table->timestamps();
+
+            $table->index(['user_id', 'stripe_status']);
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('subscription_schedules');
+    }
+};

database/migrations/2019_05_03_000003_create_quotes_table.php

@@ -0,0 +1,40 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    /**
+     * Run the migrations.
+     */
+    public function up(): void
+    {
+        Schema::create('quotes', function (Blueprint $table) {
+            $table->id();
+            $table->unsignedBigInteger('user_id');
+            $table->string('stripe_id')->unique();
+            $table->string('status');
+            $table->string('number')->nullable();
+            $table->integer('amount_subtotal')->nullable();
+            $table->integer('amount_total')->nullable();
+            $table->string('currency');
+            $table->timestamp('expires_at')->nullable();
+            $table->timestamp('status_transitions_finalized_at')->nullable();
+            $table->timestamp('status_transitions_accepted_at')->nullable();
+            $table->timestamp('status_transitions_canceled_at')->nullable();
+            $table->timestamps();
+
+            $table->index(['user_id', 'status']);
+        });
+    }
+
+    /**
+     * Reverse the migrations.
+     */
+    public function down(): void
+    {
+        Schema::dropIfExists('quotes');
+    }
+};

src/Billable.php

@@ -3,20 +3,28 @@
 namespace Laravel\Cashier;
 
 use Laravel\Cashier\Concerns\HandlesTaxes;
+use Laravel\Cashier\Concerns\ManagesBillingCredits;
 use Laravel\Cashier\Concerns\ManagesCustomer;
 use Laravel\Cashier\Concerns\ManagesInvoices;
 use Laravel\Cashier\Concerns\ManagesPaymentMethods;
+use Laravel\Cashier\Concerns\ManagesPricingModels;
+use Laravel\Cashier\Concerns\ManagesQuotes;
 use Laravel\Cashier\Concerns\ManagesSubscriptions;
+use Laravel\Cashier\Concerns\ManagesSubscriptionSchedules;
 use Laravel\Cashier\Concerns\ManagesUsageBilling;
 use Laravel\Cashier\Concerns\PerformsCharges;
 
 trait Billable
 {
     use HandlesTaxes;
+    use ManagesBillingCredits;
     use ManagesCustomer;
     use ManagesInvoices;
     use ManagesPaymentMethods;
+    use ManagesPricingModels;
+    use ManagesQuotes;
     use ManagesSubscriptions;
+    use ManagesSubscriptionSchedules;
     use ManagesUsageBilling;
     use PerformsCharges;
 }

src/CheckoutBuilder.php

@@ -11,15 +11,31 @@ class CheckoutBuilder
     use AllowsCoupons;
     use HandlesTaxes;
 
+    /**
+     * The Stripe model instance.
+     *
+     * @var \Illuminate\Database\Eloquent\Model|null
+     */
+    protected $owner;
+
+    /**
+     * The billing mode for the subscription.
+     *
+     * @var array|null
+     */
+    protected $billingMode = null;
+
     /**
      * Create a new checkout builder instance.
      *
      * @param  \Illuminate\Database\Eloquent\Model|null  $owner
      * @param  object|null  $parentInstance
      * @return void
      */
-    public function __construct(protected $owner = null, ?object $parentInstance = null)
+    public function __construct($owner = null, ?object $parentInstance = null)
     {
+        $this->owner = $owner;
+
         if ($parentInstance && in_array(AllowsCoupons::class, class_uses_recursive($parentInstance))) {
             $this->couponId = $parentInstance->couponId;
             $this->promotionCodeId = $parentInstance->promotionCodeId;
@@ -31,6 +47,23 @@ public function __construct(protected $owner = null, ?object $parentInstance = n
             $this->estimationBillingAddress = $parentInstance->estimationBillingAddress;
             $this->collectTaxIds = $parentInstance->collectTaxIds;
         }
+
+        if ($parentInstance) {
+            // Use reflection to access the protected billingMode property if it exists
+            try {
+                $reflection = new \ReflectionClass($parentInstance);
+                if ($reflection->hasProperty('billingMode')) {
+                    $property = $reflection->getProperty('billingMode');
+                    $property->setAccessible(true);
+                    $billingMode = $property->getValue($parentInstance);
+                    if ($billingMode !== null) {
+                        $this->billingMode = $billingMode;
+                    }
+                }
+            } catch (\ReflectionException $e) {
+                // Ignore reflection errors
+            }
+        }
     }
 
     /**
@@ -45,6 +78,93 @@ public static function make($owner = null, ?object $instance = null)
         return new static($owner, $instance);
     }
 
+    /**
+     * Set the billing mode for the subscription.
+     *
+     * @param  string  $type
+     * @return $this
+     */
+    public function withBillingMode($type = 'flexible')
+    {
+        $this->billingMode = ['type' => $type];
+
+        return $this;
+    }
+
+    /**
+     * Get the default billing mode from config.
+     *
+     * @return string
+     */
+    protected function getDefaultBillingMode()
+    {
+        return config('cashier.default_billing_mode', 'classic');
+    }
+
+    /**
+     * Get the effective billing mode.
+     *
+     * @return string
+     */
+    protected function getEffectiveBillingMode()
+    {
+        return $this->billingMode['type'] ?? $this->getDefaultBillingMode();
+    }
+
+    /**
+     * Get the billing mode for the Stripe payload.
+     *
+     * @return array|null
+     */
+    protected function getBillingModeForPayload()
+    {
+        $effectiveMode = $this->getEffectiveBillingMode();
+
+        // Only include billing_mode in payload if it's flexible
+        // Classic mode is Stripe's default, so we omit it for backwards compatibility
+        if ($effectiveMode === 'flexible') {
+            $this->validateFlexibleBillingSupport();
+
+            return ['type' => 'flexible'];
+        }
+
+        return null;
+    }
+
+    /**
+     * Validate that flexible billing mode is supported by the current API version.
+     *
+     * @return void
+     *
+     * @throws \InvalidArgumentException
+     */
+    protected function validateFlexibleBillingSupport()
+    {
+        $apiVersion = config('cashier.stripe.api_version') ?? \Stripe\Stripe::getApiVersion();
+
+        if ($apiVersion && version_compare($apiVersion, '2025-06-30', '<')) {
+            throw new \InvalidArgumentException(
+                'Flexible billing mode requires Stripe API version 2025-06-30.basil or later. '.
+                'Current version: '.$apiVersion.'. Please update your API version.'
+            );
+        }
+    }
+
+    /**
+     * Create a new checkout session for subscriptions.
+     *
+     * @param  array|string  $items
+     * @param  array  $sessionOptions
+     * @param  array  $customerOptions
+     * @return \Laravel\Cashier\Checkout
+     */
+    public function createSubscription($items, array $sessionOptions = [], array $customerOptions = [])
+    {
+        $sessionOptions['mode'] = 'subscription';
+
+        return $this->create($items, $sessionOptions, $customerOptions);
+    }
+
     /**
      * Create a new checkout session.
      *
@@ -75,6 +195,13 @@ public function create(string|array $items, array $sessionOptions = [], array $c
                 : [],
         ]);
 
+        // Add billing mode for subscription mode only
+        if (($sessionOptions['mode'] ?? null) === 'subscription') {
+            if ($billingMode = $this->getBillingModeForPayload()) {
+                $payload['subscription_data']['billing_mode'] = $billingMode;
+            }
+        }
+
         return Checkout::create($this->owner, array_merge($payload, $sessionOptions), $customerOptions);
     }
 }