What embedded payment processing means for your software business

Embedded payment processing lets you accept payments directly inside your application without sending customers to a separate checkout page or third-party site. Instead of building a payment system from scratch — which requires handling security certifications, compliance rules, and infrastructure — you integrate a payment processor's tools into your software. Your customers see your brand throughout the transaction, stay on your platform, and you keep more control over the experience.

For SaaS companies and independent software vendors (ISVs), this matters because payment friction costs you revenue. Every time a customer leaves your app to pay, some don't come back. Embedded processing also lets you charge for features in real time, run subscription billing without external redirects, and collect payment data you can use to understand customer behavior — all while the processor handles the compliance burden.

The tradeoff is integration work upfront and ongoing fees. You'll need a technical team to connect the processor's API to your system, test it thoroughly, and maintain it as your software evolves. But for most SaaS and ISV businesses, the revenue lift and customer retention gains justify the effort.

Key Takeaways

  • Embedded payment processing keeps customers in your app during checkout, reducing cart abandonment and improving the user experience.
  • You handle integration and ongoing maintenance, but the payment processor manages security compliance, fraud detection, and settlement.
  • Major processors like Stripe, Square, PayPal, and Adyen all offer APIs designed for software companies to embed payments into their products.
  • Costs typically include a percentage of each transaction (2–3%), a per-transaction fee (20–30 cents), or both, plus monthly minimums or gateway fees depending on the processor.
  • Your choice of processor affects which payment methods you can offer, which countries you can serve, and how much technical support you receive during integration.

How embedded payment APIs work in practice

When you embed a payment processor's API, you're using their pre-built code libraries and endpoints to handle the payment flow without leaving your application. A customer enters payment details (card number, expiration, CVV) directly into a form you control, your app sends that data securely to the processor's servers, and the processor returns a token or confirmation. Your app then records the transaction and updates the customer's account — all within your interface.

The processor never sees your customer's raw payment data; instead, they see a tokenized version that can't be reused elsewhere. This separation is what makes embedded processing compliant with PCI DSS (Payment Card Industry Data Security Standard). You don't have to store card numbers yourself, which means you avoid the most expensive and risky part of payment compliance.

Most processors offer multiple integration paths depending on your technical needs. A hosted payment form is the simplest: you embed an iframe or redirect to a form the processor hosts, so you don't touch the payment data at all. A custom form with tokenization gives you more control over the look and feel — you build the form, but the processor's JavaScript library handles the sensitive parts. A full API integration is the most flexible but requires the most engineering work.

Major processors that serve SaaS and ISV companies

Stripe is the most common choice for SaaS and ISV companies because their API is well-documented, their developer experience is smooth, and they support a wide range of payment methods and countries. They offer Stripe Payments (for one-time charges), Stripe Billing (for subscriptions), and Stripe Connect (if you need to split payments between multiple parties). Their pricing is 2.9% + 30¢ per transaction in the US, with higher rates for international cards.

Square focuses on simplicity and is strong for companies that also need in-person payments. Their online payment API is straightforward, and they offer the same payment form options as Stripe. Square charges 2.9% + 30¢ per online transaction, and they provide good support for small to mid-market ISVs. They're less common in enterprise SaaS but work well if you want a single processor for both online and physical payments.

PayPal (through their Commerce Platform) appeals to companies that want to offer PayPal as a payment method alongside cards, or that already have PayPal relationships. Their API is mature but less developer-friendly than Stripe's. Pricing varies by product tier, but typically runs 2.99% + 30¢ for standard transactions. PayPal is especially useful if your customers expect to pay with PayPal accounts.

Adyen is the choice for companies operating globally or processing high volumes. They support more payment methods and currencies than most competitors, have strong fraud prevention, and offer dedicated support for enterprise clients. Their pricing is negotiable and typically lower than Stripe at scale, but they require higher transaction volumes to justify the relationship.

Authorize.Net is an older platform still used by many ISVs, especially those with existing integrations. Their API works but is less modern than Stripe's. They charge a monthly gateway fee (around $25–$35) plus per-transaction fees, which can be cheaper for very low-volume businesses but more expensive as you scale.

What integration actually involves

Integration starts with reading the processor's API documentation and deciding which integration path fits your needs. If you choose a hosted form, integration might take a few days — you're mostly configuring settings and testing redirects. If you build a custom form, you'll spend a week or two getting the JavaScript library working, handling errors, and testing edge cases like network failures or duplicate submissions.

Your engineering team will need to handle several pieces: storing the processor's response (a transaction ID or token) in your database, reconciling what the processor reports with what your app recorded, handling webhooks (notifications from the processor when a payment succeeds, fails, or is disputed), and building a dashboard so customers can see their payment history and manage subscriptions.

Testing is the longest part. You'll test successful payments, failed cards, expired cards, 3D Secure authentication (required for some international transactions), refunds, chargebacks, and what happens when a webhook arrives late or twice. Most processors provide sandbox environments where you can test with fake card numbers before going live.

After launch, you'll maintain the integration by monitoring for API changes, handling new payment methods as they become available, and responding to customer disputes. Most processors send notifications when they deprecate old API versions, usually giving you 12–24 months to upgrade.

Pricing models and what they cost you

Payment processor pricing has three main components: a percentage of the transaction amount, a fixed per-transaction fee, and optional monthly or annual fees. Stripe and Square both charge roughly 2.9% + 30¢ per transaction, which means a $100 payment costs you $3.20. Adyen's percentage is often lower (2.5–2.7%) but requires higher volumes. Authorize.Net charges a monthly gateway fee plus per-transaction fees, which can be cheaper if you process fewer than 500 transactions per month but more expensive as volume grows.

International transactions cost more. A card issued outside the US typically costs 3.9% + 30¢ with Stripe, and some payment methods (like certain digital wallets or local bank transfers) have their own rates. If you serve customers globally, budget for an effective rate of 3–4% rather than 2.9%.

Subscription billing usually has no additional fee beyond the per-transaction rate, but some processors charge a small monthly fee if you use their subscription management tools. Refunds and chargebacks are free to process, but chargebacks (when a customer disputes a charge with their bank) can trigger a chargeback fee ($15–$100 depending on the processor) if they happen too often.

To estimate your costs, calculate your expected monthly transaction volume and average transaction size, then multiply by the processor's rate. A SaaS company processing $100,000 per month at 2.9% + 30¢ pays roughly $3,200 in fees. At $1 million per month, you're paying around $31,000 — which is why high-volume companies negotiate custom rates with Adyen or other enterprise processors.

Compliance and security responsibilities

When you embed a payment processor's API, the processor handles most of the compliance burden — they maintain PCI DSS certification, run fraud detection, and manage security updates. Your responsibility is to use their API correctly and not do anything that bypasses their security. Specifically: never store raw card data, never log payment details, and always use HTTPS for any page that handles payment information.

You'll need to sign a payment processor agreement that outlines your obligations and theirs. Read the section on data handling carefully — it specifies what you can and can't do with payment data, how long you can retain it, and what happens if you have a breach. Most processors require you to notify them within 24–72 hours if you suspect unauthorized access.

If you process payments on behalf of other businesses (for example, if you're a marketplace or a payment facilitator), you'll need additional compliance. You may need to register as a payment facilitator with your processor and the card networks, which involves more paperwork and higher compliance standards. Stripe, Square, and PayPal all support this model, but it requires more setup and ongoing monitoring.

Choosing between processors for your specific situation

Start by listing what you need: Which payment methods must you support? (Cards only, or also PayPal, Apple Pay, Google Pay, ACH transfers, international methods?) Which countries do you serve? What's your expected transaction volume? Do you need subscription billing, marketplace payments, or just one-time charges?

Stripe is the default choice for most SaaS and ISV companies because their API is excellent, their documentation is thorough, and they support nearly every payment method and country. Choose Stripe unless you have a specific reason not to.

Choose Square if you also process in-person payments or want a simpler, less feature-rich API. Choose PayPal if your customers expect PayPal as an option and you want to avoid integrating multiple processors. Choose Adyen if you're processing over $1 million per month and want to negotiate lower rates. Choose Authorize.Net only if you already have an existing integration and it's working.

Most companies start with Stripe, and most never switch. The switching cost (re-engineering, re-testing, customer communication) is high enough that you'd need a compelling reason — usually a significant rate reduction at much higher volume.

Common mistakes to avoid

The most common mistake is underestimating integration time. Developers often think "I'll just add the payment API" and expect it to take a few days. In reality, handling errors, testing edge cases, and building a payment dashboard usually takes 4–8 weeks for a first integration. Budget accordingly and don't launch until you've tested thoroughly.

The second mistake is not handling webhooks properly. When a payment succeeds or fails, the processor sends your app a notification. If your app doesn't listen for these notifications, you'll miss refunds, chargebacks, and subscription cancellations. Webhooks are easy to get wrong (they can arrive out of order, arrive twice, or arrive late), so test them extensively before launch.

The third mistake is choosing a processor based on pricing alone. A 0.1% difference in rates sounds small until you do the math, but it's meaningless if the processor's API is harder to use or their support is slower. Stripe's slightly higher rates are worth it for most companies because their developer experience saves you engineering time.

The fourth mistake is not planning for disputes and chargebacks. Some customers will dispute charges with their bank instead of asking for a refund. When that happens, the processor notifies you, and you have a window (usually 7–10 days) to respond with evidence that the charge was legitimate. If you don't respond, you lose the money. Build a system to track and respond to disputes before you launch.

Frequently Asked Questions

Can I use multiple payment processors at once?

Yes, many companies integrate Stripe for cards and PayPal separately so customers can choose their payment method. This increases your integration work and makes reconciliation more complex, but it can reduce payment failures because some customers prefer certain methods. Most companies start with one processor and add a second only if their payment decline rate is too high.

What happens if a payment processor goes down or stops serving my industry?

If your processor has an outage, your customers can't pay until it's resolved — usually a few hours. This is rare but it happens. If a processor stops serving your industry (for example, if they exit a country or stop supporting a payment method you rely on), you'll need to migrate to another processor, which takes weeks of engineering work. Choose a processor with a track record of stability and broad industry support to minimize this risk.

Do I need to handle PCI compliance myself if I use an embedded payment API?

No. If you use the processor's hosted form or tokenization library correctly, you avoid handling raw card data, which means you don't need full PCI DSS certification. You still need to run your servers securely and use HTTPS, but the processor handles the heavy compliance work. Read your processor's documentation to confirm you're using their API in a PCI-compliant way.

How long does it take to go live with embedded payments?

A simple integration with a hosted payment form can go live in 2–4 weeks. A custom form with tokenization usually takes 4–8 weeks. A full API integration with subscription billing and marketplace features can take 2–3 months. Most of this time is testing and handling edge cases, not writing code. Plan for at least a month of testing before you accept real payments.

What should I do if my payment processor raises their fees?

Processors sometimes increase rates, especially if your business model or transaction mix changes. You can negotiate if you're processing high volume, but for most SaaS companies, the rate increase is small enough to absorb. Switching processors is expensive, so only consider it if the new rate is significantly higher than competitors' rates and you're processing enough volume to justify the switching cost.