Automating tax calculation from Amazon VAT reports: a system design for VAT service providers

Description and use

The platform automates VAT calculation from Amazon reports by classifying transactions into seven categories, applying country‑specific rules, and outputting all required return boxes, reducing manual effort and errors.

Problem

VAT service providers spend excessive time and risk errors converting Amazon VAT Transactions Reports into country‑specific return boxes.

Outcome

The platform reduces manual effort, eliminates spreadsheet errors, and provides traceable calculations for VAT returns across multiple countries.

Workflow

• Upload Amazon VAT Transactions Report and deduction documents
• System classifies each row into a sales category based on tax collector, buyer VAT status, and ship‑from/ship‑to countries
• Apply country‑specific treatment table to compute output and input tax per category
• Fetch daily exchange rates and convert transaction amounts to filing currency
• Aggregate totals into UK VAT Return boxes (Box 1–9) or equivalent EU return structures
• Present calculated totals to seller for confirmation
• Seller confirms and submits; operations review calculations and manage payment proofs
• File return with accounting firm; await payment; mark filed

Evidence

Accountants sort the report in Excel by country, rate and deductible item, then copy the numbers into each country's return.

Source

Instead of writing rules country by country, we first put every transaction into one of 7 sales categories.

Source

The system fetches exchange rates daily and converts each transaction at the rate for its date.

Source

20 end‑to‑end automated tests covering the main calculation paths

Source