Helcim Billing Module

Outcome

Helcim API verified — customers, invoices, subscriptions, cards, bank accounts all working

• Full API reference documented: docs/helcim-api-reference.md
• Portal integration map: 15+ new API routes, Prisma schema changes, 3-phase build plan
• Interchange-plus pricing replaces flat-rate Stripe — lower cost per transaction
• HelcimPay.js iframe for PCI SAQ A compliance — no card data touches our servers

The Problem

Stripe pricing was eating margins on every transaction. The business needed interchange-plus pricing, ACH support, and a fully integrated billing UI within the existing client portal — without paying monthly fees for a billing platform.

The Architecture

Researched 4 processors (Helcim, Square, Paddle, GoCardless) and 3 open-source billing platforms (Lago, Kill Bill, Crater). Selected Helcim for interchange-plus pricing, no monthly fee, ACH, tokenization, and refund API. Designed full portal integration with 15+ new API routes, Prisma schema changes, and 3-phase build plan.

The Solution

Full API reference documented. Helcim API verified working — customers, invoices, subscriptions, cards, and bank accounts all tested. Portal integration mapped across 7 existing Stripe routes to replace, new PaymentMethod and RefundRecord Prisma models, and 3-phase build plan (cards+ACH, subscriptions, reports/dashboard).

Stack & Role