GrupaDSP — WooCommerce Integration with Comarch ERP XT

We automated order and invoicing processes for a HoReCa distributor by building a custom bidirectional WooCommerce ↔ Comarch ERP XT integration. The result: 99% of order-to-invoice workflow handled without human touch, dozens of operational hours reclaimed per week, and a measurable drop in pricing and stock errors that previously cost the client revenue and customer trust.

Client challenge: operational chaos

The client running an e-commerce store on WooCommerce experienced that growing sales did not equal growing efficiency. Manual processes became a bottleneck, generating critical errors and wasted time.

Critical problems we eliminated:

• Manual invoicing: Daily, time-consuming issuing and sending of invoices in Comarch ERP XT.
• No automatic synchronization: Outdated prices and stock levels in WooCommerce, leading to pricing and logistical errors.
• Data duplication and inconsistency: Duplicate customer and product records in both systems.
• Lack of control: The need to manually verify invoice-send status by entering every document individually.

The client needed one, coherent system that would automatically orchestrate processes and move control into WooCommerce.

Project goal

Build a dedicated, two-way WooCommerce ↔ Comarch ERP XT integration that achieves full automation and gives the owner immediate control.

• Goal 1: Full automation: Automate synchronization, invoicing, and document delivery.
• Goal 2: Error elimination: Remove manual work and human mistakes.
• Goal 3: Efficiency growth: Shorten order fulfillment time and improve customer service.
• Goal 4: Central control: Enable full control over orders and documents in one place (WooCommerce).

Our solution: dedicated API

We built a custom WooCommerce–Comarch ERP XT API integration, focused on maximum performance and data security.

Two-way data synchronization (products and customers)

• Mapping: Linking customers by ID or NIP, and products by unique index.
• Full consistency: First full database synchronization (Woo → Comarch).
• Daily automation: Automatic daily update of prices and stock levels (Comarch → Woo).

Benefit: Current prices and stock levels at any moment. End of data duplication and pricing errors.

Order handling automation

• Instant transfer: WooCommerce orders automatically flow to Comarch as sales documents.
• Intelligent handling: Customer identification by NIP and handling of client-specific processes (e.g. quantity modification before the invoice, handling "over-stock" orders).
• Clean database: Only updates of existing products in WooCommerce — no unnecessary record creation.

Benefit: Significantly faster order handling and preservation of the client's specific business processes.

Intelligent invoicing system (key value)

The module that eliminated the need for manual work and brought full transparency.

End-to-end invoicing process flow:

1. Proforma/Order is issued as an invoice in Comarch ERP XT.
2. The system automatically retrieves and archives the finished document in WooCommerce.
3. The invoice is automatically sent to the customer from the store's email address.
4. The order status in Woo changes to "Invoice sent" (full transparency).

Key control features:

• Cyclical monitoring: The script runs in the background every 2 hours, monitoring status and sending all invoices that haven't been sent yet.
• 1-click control: "Check FS availability and send now" button on the order card — allowing immediate send when urgently needed.
• Safety: The system ignores old invoices, preventing customers from being spammed with older documents.

Benefit:

Full automation of invoice delivery. Saves time for accounting and provides immediate transparency for the owner.

Stack and architecture

The integration sits between two systems that were never designed to talk to each other directly. Most off-the-shelf connectors fail at the edge cases that matter for HoReCa: same-NIP customer aliasing, over-stock orders, retry logic for failed invoice delivery, and idempotent re-syncs after Comarch downtime. We built it as a small, dedicated PHP service running alongside WooCommerce.

Technology choices and why

• WooCommerce custom plugin (PHP 8): integration logic lives inside WooCommerce as a plugin. No separate app server, no second admin to learn for the client. All settings exposed in WooCommerce admin.
• Comarch ERP XT REST API: bidirectional REST calls with token refresh, exponential backoff on 5xx, and a dead-letter queue for invoices that fail to send.
• Cron + WP-Cron hybrid: server-level cron for the 2-hour invoice sweep (reliability), WP-Cron for product and stock deltas (admin-controllable).
• Idempotency keys per order: every Comarch document creation is keyed by Woo order ID so retries never produce duplicate invoices.
• Audit log table: every sync attempt, success, failure and retry written to a dedicated DB table so accounting can answer "what happened to invoice X" in seconds.

Edge cases we explicitly handled

• NIP-based customer matching: identical company can buy under multiple Woo accounts; Comarch must see one customer.
• Over-stock orders: Comarch rules allow over-issuing for trusted customers; integration respects per-client policies, does not block.
• Quantity adjustments before invoicing: staff sometimes adjust order quantity in Comarch after order placement; the integration syncs the final invoice back to Woo, not the original order quantity.
• Old-invoice spam protection: 7-day age cutoff on email re-send to prevent customers receiving stale documents during a backfill.

Timeline and team

Delivered as a fixed-scope nearshore engagement. Discovery in week 1 with the client's accounting and warehouse leads, build through week 6, parallel-run testing weeks 7 and 8, cutover at end of week 8.

Team composition

• 1 senior PHP/WooCommerce engineer (lead): owned the plugin architecture, Comarch API integration, and edge-case handling.
• 1 mid-level backend engineer: wrote the audit log layer, retry logic and admin UI.
• 0.5 PM: weekly status with the client, scope decisions, change-order management.
• 0.25 QA: parallel-run validation against last 90 days of historical orders.

Engagement model

Fixed scope, fixed budget, weekly demos with the client's accounting lead. We did not bill for "discovery hours" outside week 1. Code committed to the client's GitHub from day one with full IP transfer.

Deployment results

The dedicated API integration translated into immediate and measurable results in key operational areas of the client:

• 99% process automation: We achieved full automation of the path: Order in WooCommerce → Invoice issuance in Comarch → Email delivery to customer. All key stages now happen without human involvement.
• Full data consistency: Thanks to automatic synchronization of prices, stock levels, and customer data, manual errors and the risk of selling out-of-stock products were eliminated.
• Time savings: The client saves dozens of minutes every day previously spent on manual invoice issuance and delivery. The system handles this work automatically every two hours.
• Greater owner control: Full visibility of invoice status (sent/unsent) and the ability to manually send immediately with one click — available directly in WooCommerce, much more conveniently than in the ERP.
• Better customer service: Every customer receives the invoice automatically and at the right moment after placing the order.

What the client said:

"The integration works very well, this solution is great. Through WooCommerce I can see immediately what's missing — much more conveniently!"

Summary

We built a complete, dedicated system integrating WooCommerce with Comarch ERP XT that eliminates errors, automates key logistical and operational processes, and provides full transparency and control.

This is the ideal solution for companies that want to grow online sales without increasing operational load.

Related services

This was a fixed-scope, ERP-integration nearshore engagement. If you have a similar shape of problem, here are the engagement models we typically use:

For broader context on hiring Polish engineering teams, see nearshore software development or cost of nearshore software development 2026.