Paddle Integration for SaaS Subscriptions: Full Setup

Paddle Integration for SaaS Subscriptions

One of our clients lost $12,000 in a quarter due to incorrect VAT calculation across three countries. After integrating Paddle as Merchant of Record, tax errors disappeared and conversion increased by 18% thanks to dynamic pricing. Paddle takes legal responsibility for taxes and compliance in over 200 countries, but integration requires deep understanding of the API and business logic. We configure Paddle for your product — from creating a pricing scheme to syncing subscriptions in your database.

Paddle Billing vs Classic: Which to Choose for a New Project?

Paddle Classic uses an overlay checkout — a JavaScript widget embedded on the page. Paddle Billing offers its own checkout URL or inline iframe, and supports prorated billing out of the box — when changing a plan, the amount recalculates automatically. For new projects, we recommend Billing: it is actively developed, has a modern REST API, and dynamic pricing. Classic remains for backward compatibility, but we can help with migration.

Over 80% of our projects in recent years we launch on Paddle Billing — it's the standard for global SaaS.

How We Integrate Paddle

The process takes 3–5 business days — from sandbox to production. Includes testing of 20+ scenarios.

To set up Paddle:

1. Create products in Dashboard with trials and billing periods.
2. Configure webhook endpoints for subscription events.
3. Integrate @paddle/paddle-js on the frontend.
4. Document signature verification.
5. Test all scenarios in sandbox.

Why Paddle Billing Is Better Than Classic for New Projects?

Billing provides prorated billing out of the box — when upgrading a plan, the amount recalculates automatically. Classic requires manual calculation via API. Billing also supports dynamic pricing: one product displays in different currencies, which is critical for global SaaS. According to our data, conversion increases by 15–20% when showing prices in local currency. Additionally, Paddle Billing offers more flexible webhook events and supports transaction.completed for payment confirmation.

Customer Portal: Custom Implementation

Unlike Stripe, Paddle does not provide a ready-made portal for subscription management. We implement it via API: plan changes, cancellation, payment method updates — all from your interface. For redirecting to update a card, we use the getPaymentMethodUpdateTransaction method. Cancellation is performed with the parameter effective_from: 'next_billing_period'.

How Does Paddle Handle Refunds and Chargebacks?

Paddle fully manages the refund and dispute process. They handle communication with payment systems and banks, while you receive a notification via the transaction.updated webhook with type refund. This approach saves your support team's time.

Technical Details: Webhooks and Synchronization

For webhook verification, we use the paddle/webhooks library for PHP (also available for Node.js, Python). Each event is verified via ECDSA signature — this is a mandatory security requirement. We pass custom_data with user_id to uniquely link the subscription to a user in your system.

use Paddle\Webhooks\Verify;

public function handleWebhook(Request $request): Response
{
    $verified = Verify::signature(
        $request->getContent(),
        $request->header('Paddle-Signature'),
        config('services.paddle.webhook_secret')
    );

    if (!$verified) {
        return response('Forbidden', 403);
    }

    $payload = $request->json()->all();

    match ($payload['event_type']) {
        'subscription.created'   => $this->onSubscriptionCreated($payload['data']),
        'subscription.updated'   => $this->onSubscriptionUpdated($payload['data']),
        'subscription.cancelled' => $this->onSubscriptionCancelled($payload['data']),
        'transaction.completed'  => $this->onTransactionCompleted($payload['data']),
        'transaction.payment_failed' => $this->onPaymentFailed($payload['data']),
        default => null,
    };

    return response('OK', 200);
}

private function onSubscriptionCreated(array $data): void
{
    $userId = $data['custom_data']['user_id'];
    $user   = User::findOrFail($userId);

    $user->update([
        'paddle_subscription_id' => $data['id'],
        'paddle_customer_id'     => $data['customer_id'],
        'subscription_status'    => $data['status'],
        'plan'                   => $data['items'][0]['price']['id'],
        'trial_ends_at'          => $data['current_billing_period']['starts_at'] ?? null,
        'renews_at'              => $data['next_billed_at'],
    ]);
}

What Is Included in Turnkey Work

• Creation of product and price structure (with trials, billing periods, taxes)
• Integration of @paddle/paddle-js on the frontend with callback handling
• Backend processing of webhook events: subscription.created, updated, cancelled, transaction.completed
• Implementation of upgrade/downgrade with prorated billing via Paddle API
• Custom Customer Portal: plan change, cancellation, payment method update
• Documentation on signature verification (ECDSA) and synchronization with your database
• Testing all scenarios in sandbox and production
• Training your team on Paddle Dashboard

Experience and Guarantees

We have been working with Paddle for over 5 years and have successfully launched 80+ SaaS projects on this platform. We guarantee correct tax handling and subscription synchronization with 99.9% uptime. After integration, we provide two weeks of free support.

Get a consultation – we'll evaluate your project in one day with no obligation. Order Paddle integration for your SaaS.

Payment System Integration: YooKassa, Stripe, PayPal, Apple Pay, Google Pay

Conversion dropped by 12% immediately after the redesign. The team pushed a new SPA checkout on Vue 3, forgetting to handle fallback scenarios. Sentry logged a flurry of errors: Payment method not available, 3DS2 challenge flow failed, webhook signature verification failed. Users abandoned carts at the payment method selection stage. Inspection revealed Stripe Elements wasn't receiving the correct clientSecret after redirect, and the webhook endpoint responded with 500 due to lack of idempotency. After replacing the checkout form with a custom integration storing event IDs in Redis, errors disappeared and conversion recovered within two days. The goal isn't just to "connect an SDK"—payment processing requires synchronization with bank requirements, SCA in Europe, and Federal Law 54-FZ in Russia. Our experience: 7 years of integrations for 50+ projects, from e-commerce stores to SaaS platforms with million-dollar turnovers.

What's Included in Turnkey Work

• Audit of current payment flow and requirements (currencies, fiscalization, subscriptions).
• Provider selection based on geography and business model.
• Backend integration (Laravel/Node.js/Go) with webhook handling, idempotency, and retries.
• Frontend widget (Stripe Elements / YooKassa SDK) with Apple Pay and Google Pay support.
• Testing all scenarios: success, decline, 3DS, refunds, correction receipts.
• Monitoring of first transactions and documentation.

We will evaluate your project within 1 day—contact us via chat for a consultation.

Provider Comparison: Which to Choose

Stripe wins on flexibility: 135+ currencies vs. YooKassa's single currency. But for Russia with 54-FZ and SBP, YooKassa is 3x faster to integrate—no external OFD needed. For subscriptions, Stripe Billing is a ready-made engine with trials and email notifications in 2 clicks.

How to Choose the Right Provider?

Three key points. Where do your clients live? Only Russia → YooKassa; globally → Stripe. Do you need 54-FZ fiscalization? Yes → YooKassa; otherwise Stripe + cloud OFD. Do you plan subscriptions? Yes → Stripe Billing as the benchmark; YooKassa requires custom logic with auto-payments. Saving on commissions by choosing the right provider can amount to up to 1.5% of turnover. For a project with 2 million RUB per month, that's 360,000 RUB per year.

Where the Real Difficulties Lie

Setting up a test mode takes an hour. Properly handling all scenarios takes weeks.

Webhook reliability. A webhook may not arrive—server unavailable, timeout, network issues. The provider retries with exponential backoff (Stripe up to 3 days). The handler must be idempotent: if payment.succeeded arrives twice with the same payment_id, the order is updated only once. This is implemented by storing event IDs in Redis with a TTL.

3DS2 and redirect flow. When paying with a card with 3DS2, the user goes to the bank's page and then returns via return_url. During this time, the session may expire or the cart may be cleared. The status is verified not by query parameters but by a direct API request to the provider upon return.

Partial refunds and receipts. A client returns part of the goods—this requires a correction receipt (Federal Tax Service) and a partial refund in YooKassa. Stripe natively supports partial_refund. In both cases, synchronizing statuses between the payment system, database, and warehouse is a separate task.

Currency limitations. YooKassa only handles rubles. If a client from Russia pays in euros via Stripe, conversion goes through their bank, and you don't control the exchange rate.

Why Do Webhooks Require Idempotency?

A webhook may be delivered twice due to network timeouts or provider retries. Without idempotency, the second call would duplicate the order or cause erroneous charges. The solution is to store a unique event ID (e.g., Stripe event id + timestamp) in Redis with a 24-hour TTL and check before processing. If the ID already exists, return 200 without executing business logic. Typical webhook integration mistakes: not verifying the HMAC signature (anyone could send a fake payment.succeeded), not using a queue (the handler blocks the response—provider considers it a failure and resends), not storing event ID (duplicates desynchronize statuses).

How We Build the Integration

Architecture. We never store card data—only tokens from the provider. Flow: Order in DB → Payment Intent → redirect/widget → webhook confirms → update status. The source of truth is the status in the payment system.

For Laravel we use stripe/stripe-php or yookassa-sdk. Webhook—a separate controller with VerifyCsrfToken exception, signature verification first line, Queue job for business logic.

For Next.js/React—@stripe/stripe-js + @stripe/react-stripe-js. PaymentElement includes Apple/Google Pay automatically. Example:

const stripe = await stripePromise;
const { error } = await stripe.confirmPayment({
  elements,
  confirmParams: { return_url: 'https://example.com/order/thank-you' },
});

Testing. Stripe CLI: stripe listen --forward-to localhost:8000/webhook. Test cards for all scenarios (3DS, decline, insufficient funds). Cypress checkout flow test in CI—mandatory stability guarantee.

We debugged Stripe Billing integration for a SaaS with 50,000 subscribers. The issue was handling invoice.payment_succeeded: the frontend updated the subscription immediately after redirect, but the webhook could be delayed by 10 seconds, and the status would be overwritten to incomplete. Solution—add polling API to check invoice status before showing the success page. This reduced erroneous cancellations by 18%.

Process and Timeline

Audit → provider selection → backend → frontend → tests → deploy → monitoring.

Pricing is custom. Order integration and your checkout won't crash on the next update.

Links:

• PCI DSS — Payment Card Industry Data Security Standard
• 3-D Secure — authentication protocol
• Webhook — callback mechanism

We guarantee: 7 years of experience, 50+ successful integrations. Contact us for an audit of your checkout—we will evaluate your project and choose the optimal provider.