Payment gateway integration costs range from nothing to several thousand dollars, depending on whether you build it yourself, use a plug-and-play solution, or hire a developer.
If you use a hosted checkout (Stripe Checkout, Square Online, PayPal Commerce Platform), there is no integration cost—you embed a few lines of code or a button. If you build a custom integration into your own website or app, you pay a developer anywhere from $500 to $5,000 for straightforward work, or $10,000+ if your system is complex or needs to connect to inventory, accounting, or subscription software. If you use a third-party integrator or agency, expect $2,000 to $15,000 depending on scope.
Beyond the one-time build cost, you also pay transaction fees every time a customer pays. Those fees—typically 2.2% to 3.5% of the transaction amount plus a per-transaction charge—are separate from integration costs and continue indefinitely. Some gateways also charge monthly minimums or monthly software fees, which add up over time.
Key Takeaways
- Hosted checkouts (Stripe, Square, PayPal) have zero integration cost because the gateway handles the interface; you only pay per transaction.
- Custom integration into your own website costs $500 to $5,000 for a developer to build, plus ongoing transaction fees to the gateway.
- Monthly gateway fees, PCI compliance costs, and fraud tools can add $50 to $500 per month on top of per-transaction charges.
- The cheapest route for a small business is usually a hosted solution with no setup fee; the most expensive is a fully custom build with a dedicated payment team.
Hosted Checkouts: Zero Setup, Pay Per Transaction
A hosted checkout is a pre-built payment form that lives on the gateway's servers, not yours. You link to it or embed it as a button. Stripe Checkout, Square Online Checkout, and PayPal Commerce Platform all work this way. There is no integration cost because you are not building anything—the gateway provides the interface.
You pay only when a customer completes a transaction. Stripe charges 2.9% + $0.30 per card transaction in the US; Square charges 2.6% + $0.30; PayPal charges 2.99% + $0.30. These fees apply to every sale. If you process $10,000 in sales per month, you pay roughly $290 to $300 in fees that month. There is no monthly minimum or setup fee.
Hosted checkouts are fastest to launch—often same day—and require almost no technical work. The tradeoff is that you have less control over the look and feel of the payment form, and you cannot deeply customize the experience for your specific workflow.
Custom Integration: Developer Cost Plus Ongoing Fees
A custom integration means a developer builds the payment form directly into your website or app, using the gateway's API. The form lives on your domain, not the gateway's. This gives you full control over design and behavior, but it costs money upfront and requires ongoing maintenance.
A straightforward custom integration—a single payment form that accepts cards and sends data to the gateway—typically costs $500 to $2,000 if you hire a freelance developer. If your business needs the form to talk to your inventory system, accounting software, or subscription billing tool, the cost rises to $3,000 to $10,000. Complex integrations with multiple payment methods, fraud detection, and recurring billing can reach $15,000 or more.
After launch, you pay the gateway's transaction fees (2.2% to 3.5% + per-transaction charge) every month. Some gateways also charge a monthly software fee ($20 to $100) or require you to maintain PCI compliance, which may cost $500 to $2,000 per year depending on your setup. If you need fraud tools, chargeback protection, or advanced reporting, those are additional monthly costs ($50 to $500).
Monthly Fees and Hidden Costs
Transaction fees are not the only ongoing expense. Many gateways charge a monthly minimum or monthly gateway fee. Authorize.net charges $25 per month plus transaction fees. Square charges no monthly fee but takes a higher percentage per transaction. Stripe has no monthly minimum in most cases.
If you process fewer than 100 transactions per month, a monthly minimum can cost more than your actual transaction fees. For example, if Authorize.net charges $25 per month and you only process $50 in sales (which would normally cost $1.50 in fees), you pay the full $25 minimum.
PCI compliance is another cost. If your custom integration stores or handles raw card data, you must maintain PCI DSS (Payment Card Industry Data Security Standard) compliance. This can mean annual audits ($500 to $2,000), security software ($100 to $500 per year), or hiring a compliance consultant. Most businesses avoid this by using tokenization—the gateway stores the card, you store only a token—which is cheaper and simpler.
Fraud detection, chargeback protection, and advanced reporting tools add $50 to $500 per month depending on the gateway and your sales volume.
Comparing Setup Costs Across Common Scenarios
| Scenario | Setup Cost | Monthly Fees | Per-Transaction Cost |
|---|---|---|---|
| Hosted checkout (Stripe, Square, PayPal) | $0 | $0 | 2.6%–3.5% + $0.30 |
| Simple custom integration (freelance developer) | $500–$2,000 | $0–$100 | 2.2%–3.5% + $0.30 |
| Custom integration with accounting sync | $3,000–$10,000 | $50–$200 | 2.2%–3.5% + $0.30 |
| Enterprise integration with fraud tools | $10,000–$50,000 | $200–$1,000 | 1.5%–3.5% + $0.30 |
When to Use a Third-Party Integrator
If you do not have a developer on staff and do not want to hire a freelancer, you can hire a payment integrator or agency. These companies specialize in connecting payment gateways to your existing systems. They handle the technical work and manage the relationship with the gateway.
Third-party integrators typically charge $2,000 to $15,000 for the integration, depending on complexity. They may also take a small percentage of your transaction fees (0.1% to 0.5%) as an ongoing commission. This route is more expensive upfront but useful if your business has unusual requirements—multiple payment methods, international transactions, or tight deadlines.
Before hiring an integrator, ask whether they will hand over the integration to you afterward or lock you into an ongoing relationship. Some integrators own the integration and charge you monthly to use it; others build it for you to own and maintain.
Reducing Integration Costs
Start with a hosted checkout if you are new to payments. You pay zero setup cost and can launch in hours. As your business grows and you need more control, you can migrate to a custom integration later—the gateway's API will be the same, so a developer can build on top of what you already have.
Use a gateway that offers good documentation and pre-built libraries for your technology stack (JavaScript, Python, PHP, etc.). Gateways like Stripe and Square have extensive code examples, which means a developer can build faster and cheaper. Obscure gateways with poor documentation cost more to integrate because the developer has to figure out the system from scratch.
If you need your payment form to talk to other software, check whether the gateway already has a pre-built connector. Zapier, Make, and Integromat offer no-code integrations between payment gateways and accounting, CRM, and email tools. These cost $20 to $100 per month but can save you thousands in developer time.
Avoid storing card data yourself. Use tokenization (the gateway stores the card, you store a token) or hosted checkouts. Storing raw card data requires PCI compliance, which is expensive and risky.
Frequently Asked Questions
Do I have to pay setup fees if I use Stripe or Square?
No. Stripe and Square have no setup fees or monthly minimums. You pay only when a customer completes a transaction. If you use their hosted checkout, there is zero integration cost. If you build a custom integration yourself, you only pay your developer's time, not the gateway.
What is the difference between a hosted checkout and a custom integration?
A hosted checkout is a pre-built form on the gateway's servers; you link to it or embed it. Zero setup cost, but less control over design. A custom integration is a form on your own website built with the gateway's API; you pay a developer upfront, but you own the form and can customize it fully.
Do I need PCI compliance if I use a hosted checkout?
No. Hosted checkouts handle PCI compliance for you because the gateway stores the card data, not you. Custom integrations using tokenization also avoid PCI compliance costs because you store only a token, not the card itself. You only need PCI compliance if you store raw card data on your own servers.
Can I switch payment gateways after I build a custom integration?
Yes, but it costs money. A developer will need to rebuild the integration to work with the new gateway's API. The cost depends on complexity but is usually 30% to 50% of the original integration cost. To minimize switching costs, use a gateway with good documentation and avoid building custom features that are specific to one gateway.
What happens if my sales volume is very low—do I still pay monthly fees?
It depends on the gateway. Stripe and Square have no monthly minimums, so you pay only per transaction. Authorize.net charges $25 per month regardless of sales volume. If you process fewer than 100 transactions per month, a hosted solution like Stripe is cheaper than a gateway with a monthly minimum.