Automated VAT Filing & E‑Invoicing Platform for SAP-Driven Operations

It started with a hallway conversation at a digital finance conference in Vienna. The client’s Head of Compliance casually mentioned how their Polish branch was battling spreadsheets and schema errors to keep up with SAF-T and KSeF mandates. That small remark turned into a deeper technical discussion — and, weeks later, into a project kickoff.

Devox Software was engaged to design and deliver a tightly integrated compliance platform — one that would automate VAT filings, enable real-time e-invoicing via KSeF and PEPPOL, and ensure full audit resilience. The system had to work within their existing SAP S/4HANA landscape, support Poland’s transition to Continuous Transaction Control, and eliminate the manual overhead of tax operations.

• 1 Solution Architect
• 2 SAP Developers (ABAP & Fiori)
• 1 Node.js Engineer
• 1 Angular Frontend Developer
• 1 QA Automation Specialist
• 1 Business Analyst (Tax Compliance)

Complex and evolving Polish tax regulations

The Polish tax landscape was shifting rapidly — from traditional monthly VAT filings to real-time reporting and structured e-invoicing via KSeF. The client had to comply with multiple mandatory formats (JPK_VAT, JPK_KR), each with strict schema definitions and version updates. Adapting to these changes manually or retrofitting SAP reports wasn’t sustainable.

High transaction volume with no margin for error

The client processed tens of thousands of invoices monthly across multiple business units. Even minor errors in VAT categorization or SAF-T generation could trigger audit flags or submission rejections. Compliance at this scale required automation that was both precise and resilient.

Lack of real-time visibility into compliance status

There was no centralized system to track which filings were complete, which invoices were accepted by KSeF, or where issues had occurred. This created blind spots for the compliance team — especially in the final days before submission deadlines, when stakes were highest.

SAP integration constraints

The client’s SAP S/4HANA system was highly customized and already under performance load. Any new compliance solution needed to integrate deeply but non-invasively, without disrupting core operations, slowing down posting processes, or creating data inconsistencies.

Manual work and audit anxiety

Preparing JPK reports involved extracting data into spreadsheets, manually mapping tax codes, and checking against SAP ledgers. Invoices were cross-checked individually. This wasn’t just time-consuming — it exposed the company to human error, delayed filings, and a lack of reliable audit trails.

Preparing for Continuous Transaction Control (CTC)

While e‑invoicing was voluntary during the project start, mandatory KSeF was imminent. The client didn’t just need a short-term solution — they needed a future-proof platform that could support real-time validation, digital signatures, and bi-directional communication with tax authorities.