A Clean-Core Approach to Indirect Tax Compliance for SAP Enterprises

Indirect tax has grown harder to manage inside SAP environments.

Governments worldwide are expanding e-invoicing and continuous transaction control mandates, forcing companies to validate and report tax data in real time. Jurisdictional complexity compounds the problem: businesses selling across states or countries navigate thousands of overlapping tax rules that shift constantly.

Christian Jensen, Avalara’s senior director of strategic implementation partnerships, addressed these challenges in a June 17 webinar hosted by Americas’ SAP Users’ Group (ASUG). He framed the session as a technical map for tax and IT teams working through public cloud migrations, explaining how Avalara is rebuilding tax compliance for SAP S/4HANA Public Cloud as an extension of SAP Business Technology Platform (SAP BTP).

AvaTax Brings Real-Time Tax Determination to SAP BTP

Inside SAP, the customization habit is old and hard to break. Jensen said tax logic has traditionally been built directly into the ERP, which means rework with every upgrade.

Point-to-point integrations and siloed processes add friction, limiting visibility into tax data and driving up maintenance costs, he said. Hybrid landscapes fragment the picture further, and inconsistent records remain a source of calculation errors and audit exposure.

Avalara’s answer is architectural: it built AvaTax as an extension layer on SAP BTP. That choice keeps tax calculations outside the core ERP and in line with SAP’s clean-core principle, which limits custom code inside the system.

AvaTax performs real-time tax determination through centralized tax services instead of duplicating logic system by system, Jensen said. Master data validation runs across customer, vendor, material, and financial records. The system checks whether tax registrations and exemption certificates are current, and whether products and accounts are classified correctly, before any of them reaches the calculation step.

Use tax review gets the same treatment. Jensen described a shift away from manual accounts-payable reviews and spreadsheet sampling toward real-time analysis of AP data, a change he tied to gains in tax team efficiency, compliance, and visibility.

What Tax, IT, and Finance Teams Stand to Gain

Implementation timelines for AvaTax on SAP BTP take roughly six weeks, Jensen said, depending on legal-entity count, jurisdictional footprint, and product-catalog complexity.

Avalara provides its own SAP BTP tenant for customers, so they don’t need to license and stand one up separately, which Jensen said keeps the IT lift minimal and leaves tax policy management with the tax department.

Jensen pointed to Avalara’s multi-cloud architecture next, which runs active-active across Amazon Web Services, Google Cloud, Oracle Cloud Infrastructure, and Microsoft Azure with automatic failover between them. He illustrated the stakes with an eight-hour SAP billing run: a mid-run outage on one cloud provider would not stop tax calculation because the workload can shift providers without interruption.

A faster rollout and a system that keeps running through outages both mean fewer unplanned costs hitting the budget. Jensen tied that reliability to longer-term scalability, saying it gives finance the headroom to support acquisitions or expansion into new markets without adding tax-infrastructure work to the list.

What This Means for SAPinsiders

• Agentic AI tools move into tax and compliance workflows. Vendors are layering AI onto the same real-time reporting and validation demands driving e-invoicing mandates. Finance teams piloting these tools are prioritizing systems that can trace and explain decisions as jurisdictional reporting requirements keep multiplying.
• Clean core mandates push tax logic onto the platform layer. The approach discourages custom code inside SAP S/4HANA, shifting specialized functions like tax determination to SAP BTP extensions instead. Enterprises modernizing under clean core mandates are prioritizing BTP-based extensions over further customization of S/4HANA itself.
• SAP’s public cloud tax coverage moves toward global scope. Native tax calculation today spans only the US and Brazil, with broader expansion still unconfirmed by SAP. Organizations evaluating SAP BTP-based tax tools are building flexibility into rollouts to absorb expanded coverage once SAP delivers it