The internal reuse of software components owned by organizational units in different countries constitutes an implicit form of licensing that may be taxable under international regulations, making tax authorities an often overlooked stakeholder in software architecture. This study assesses to what extent a deliberately minimal software architecture description can make implicit cross-border licensing visible and interpretable for tax experts. We define a deliberately minimal architecture viewpoint based on components, dependencies, ownership, and jurisdiction, and construct a view for a large-scale industrial microservice software system comprising 2,518 components and 16,533 dependencies. The resulting architecture description is evaluated in a judgment study with four experienced tax auditors and tax advisors using semi-structured interviews. The results show that the software architecture description provides a structured, evidence-based starting point for identifying cross-border reuse and supports tax audit discussions. However, experts consistently report limitations, including mismatches between software engineering and legal notions of ownership, unclear jurisdictional assignments, and the perceived risk of interpreting dependency counts as indicators of economic value. These limitations persist despite detailed architectural data. We conclude that software architecture descriptions can expose structurally relevant reuse relationships but cannot, on their own, support the legally meaningful interpretations required for tax assessment, indicating a fundamental mismatch between architectural abstractions and taxation concepts.

翻译：不同国家组织单元所拥有的软件组件的内部重用构成了一种隐性许可形式，可能依据国际法规需要纳税，这使得税务部门成为软件架构中常被忽视的利益相关者。本研究评估了一种刻意简化的软件架构描述能在多大程度上使隐性的跨境许可对税务专家可见且可解释。我们基于组件、依赖关系、所有权和管辖权定义了一个刻意简化的架构视点，并为包含2,518个组件和16,533个依赖关系的大规模工业微服务软件系统构建了一个视图。通过半结构化访谈，与四位经验丰富的税务审计师和税务顾问进行判断研究，对所得到的架构描述进行了评估。结果表明，该软件架构描述为识别跨境重用提供了结构化、基于证据的起点，并支持税务审计讨论。然而，专家们一致报告了局限性，包括软件工程与法律所有权概念之间的不匹配、管辖权归属不明确以及将依赖计数解释为经济价值指标的感知风险。尽管拥有详细的架构数据，这些局限性依然存在。我们得出结论：软件架构描述可以暴露结构相关的重用关系，但本身无法支持税务评估所需的法律意义解释，这表明架构抽象与税务概念之间存在根本性不匹配。