Skip to content
agentusehub
Sign in+ Submit
Work & OperationsAny

Process supplier invoices from Gmail through approval and payment

An n8n pipeline extracts invoice data, checks duplicates and suppliers, routes high-value invoices for approval, then creates accounting entries and schedules payment.

Read the experience
Time saved
Not reported
Setup time
Not reported
Running cost
Not reported
Cost range
Not reported

Use case overview

An n8n pipeline extracts invoice data, checks duplicates and suppliers, routes high-value invoices for approval, then creates accounting entries and schedules payment.

Read the original report ↗

Reported experience

  1. What they did

    This is Part 1 of a 3-part series, and it covers the infrastructure only. The author runs n8n in queue mode with PostgreSQL and Redis in Docker, plus a worker. Tables for suppliers, invoices and an audit log are set up, along with Gmail, OpenAI, Postgres and Slack credentials. The planned flow is Gmail, OCR, AI extraction, duplicate and supplier checks, classification, approval, journal entry, payment.

  2. How it went

    No results or numbers yet. The article ends with a running stack and schema ready. The extraction, validation, approval and accounting steps are left to Parts 2 and 3.

  3. Worth knowing

    Queue mode can retry stalled jobs, so each step must be idempotent. That is why duplicate detection matters, and why the n8n encryption key needs a backup.

Example prompts

Try with n8n
Build an n8n workflow that watches Gmail label [invoices] for supplier invoices, extracts supplier, amount, due date and invoice number, and checks for duplicates and known suppliers in [my supplier sheet]. Invoices over [amount] should go to [approver] for approval. It's finished when a test invoice reaches the approval step; pause before creating any accounting entry or scheduling any payment and show me the details.

Related use cases

Sales · Beginner
  1. Form submit
  2. Fetch company site
  3. Claude scores fit

Auto-qualify inbound leads before a rep sees them

Score every demo request against your ICP, update HubSpot and ping the right rep in Slack within a minute of the form submit.

n8n · Claude · HubSpot · Slack
Customer Support · Intermediate
  1. New ticket webhook
  2. Claude classifies
  3. Draft from help docs

Triage support tickets and draft first replies

Every new Zendesk ticket gets a category, priority and sentiment tag plus a draft reply in an internal note before an agent opens it.

Zendesk · n8n · Claude