Payment Gateway Software: Build vs. Buy Analysis for Growing Businesses

Every WooCommerce merchant using a payment gateway is implicitly making a build vs. buy decision. Some merchants and development teams consider building custom payment integration or their own gateway interface. This guide provides the rigorous analysis that decision deserves.

What “Building” Payment Gateway Software Actually Means

1. Custom WooCommerce checkout UI: Building a custom checkout experience using an existing payment provider’s drop-in component or API. Mostly frontend work; payment processing still managed by the provider.
2. API integration: Building directly against a payment processor’s API rather than using their WooCommerce plugin. More flexibility, more maintenance burden.
3. Custom payment gateway: Building the entire payment acceptance layer, your own tokenization, your own PAN handling, your own connection to an acquirer. Extremely rare and extremely expensive.

Build Analysis: True Costs

Custom Checkout UI

• Initial development: 40–80 developer hours ($4,000–$8,000)
• Ongoing maintenance: 5–15 hours/month
• PCI scope: SAQ A if using provider’s drop-in component correctly
• Total first-year cost: $10,000–$25,000

Custom API Integration

• Initial development: 100–300 developer hours ($10,000–$30,000)
• Ongoing maintenance: 10–30 hours/month
• Annual QSA assessment if SAQ D: $15,000–$50,000
• Total first-year cost: $50,000–$150,000+

Full Custom Gateway

• Development: 2,000+ hours; multiple engineers for 12–18 months
• Card network registration and compliance: $200,000+
• Ongoing security and compliance: $100,000+/year
• Total build cost: $1M–$5M+

Buy Analysis: What You Get

A mature WooCommerce payment plugin (like ConvesioPay’s) provides:

• All payment functionality implemented and tested: zero development hours to get started
• PCI DSS Level 1 compliance through the provider: minimal merchant scope
• Ongoing maintenance: provider handles API updates, browser compatibility, new payment methods
• Fraud tools, 3DS, network tokenization: built-in capabilities
• 24/7 technical support

The Opportunity Cost Argument

The most important build vs. buy consideration isn’t direct cost, it’s opportunity cost. Every engineer hour spent building and maintaining custom payment software is an hour not spent on your core product. For most WooCommerce businesses, payments are infrastructure, not differentiation.

ConvesioPay’s WooCommerce plugin is the buy-side answer: zero development investment to start, full payment functionality out of the box, Adyen’s institutional infrastructure without the infrastructure build. Flat rate: 2.9% + $0.30, no monthly fees.