Automate GST/VAT tax returns with OpenAI, Gmail and government portal integration
Ready for 3.0Ready for 3.0. This template uses no nodes that n8n 3.0 removes. No removed nodes, versions or helpers found. Static check, last run 2026-10-19.
What this workflow does
This AI workflow has 19 nodes and runs on a schedule (every month at 09:00). Along the way it connects OpenAI Chat Model and Gmail.
How it runs
Trigger: On a schedule (every month at 09:00).
- Workflow Configuration (Edit Fields (Set)): sets 8 fields: revenueApiUrl, expensesApiUrl, invoicesApiUrl…
- Fetch Expenses Data (HTTP Request): calls an HTTP API
- Fetch Invoices Data (HTTP Request): calls an HTTP API
- Fetch Revenue Data (HTTP Request): calls an HTTP API
- Merge Financial Data (Edit Fields (Set)): sets 4 fields: revenueData, expensesData, invoicesData…
- Tax Validation & Calculation Agent (AI Agent): runs an AI agent, with model: OpenAI Chat Model; 1 tool (Calculator); output parser: Tax Calculation Output Parser
- Check Tax Threshold (If): checks a condition and branches into true / false
- Generate Tax Declaration (Edit Fields (Set)): sets 4 fields: declarationType, filingPeriod, declarationDate…
- Below Threshold Notice (Edit Fields (Set)): sets 3 fields: message, threshold, actualRevenue
- Submit to Government Portal (HTTP Request): calls an HTTP API (POST)
…plus 5 more steps. See the full node list below.
Services it uses
Before you upgrade to n8n 3.0
Nothing in this workflow is removed in n8n 3.0, so it should import and run after the upgrade.
Nodes used (9)
- Schedule Trigger
n8n-nodes-base.scheduleTrigger - Edit Fields (Set)
n8n-nodes-base.set - HTTP Request
n8n-nodes-base.httpRequest - AI Agent
@n8n/n8n-nodes-langchain.agent - OpenAI Chat Model
@n8n/n8n-nodes-langchain.lmChatOpenAi - Structured Output Parser
@n8n/n8n-nodes-langchain.outputParserStructured - Calculator
@n8n/n8n-nodes-langchain.toolCalculator - If
n8n-nodes-base.if - Gmail
n8n-nodes-base.gmail
From the author
How It Works Automates financial aggregation, validation, and intelligent tax assessment. Integrates revenue, expenses, and invoices via scheduled connectors, merges data into unified records, and applies AI-driven analysis for anomaly detection and tax…