Making n8n Workflows for Supplier Invoices and Employee Hours Reliable
Reviewed a Canadian business's n8n workflows for supplier invoices and employee hours, with the goal of making them reliable, able to scale and documented.
- Client
- Canada-based business owner
- Industry
- Accounting and operations
- Timeline
- Nov to Dec 2025
- Engagement
- Hourly
The system, step by step
In this case study, we cover a review of a client's existing n8n workflows. They already ran supplier invoices into QuickBooks Online and employee hours into dashboards, and needed them to stand up to real use.
Supplier mail
Invoices arrive
Supabase
Idempotent writes, retries, logs
QuickBooks Online
Bills created once
Dashboards
Hours and finance reporting
What the brief demanded
The client's own brief set the standard the workflows had to meet:
The client
The client was a Canada-based business owner running their back office on n8n, Supabase and QuickBooks Online, and planning to onboard more clients onto the same setup.
- Idempotent runs, so a repeated trigger does not create duplicates.
- Error handling, retry logic and logging that make failures visible.
- Supplier invoices flowing from mail into Supabase and on to QuickBooks Online.
- Employee hours flowing from ClockShark into Supabase, then dashboards and financial reporting.
- Documentation clear enough to onboard new clients.
Built and handed over
The engagement covered the review and optimisation of three workflows the client shared: an invoice agent, a QuickBooks invoice workflow and an embeddings generator, along with the documentation of how data moves between them.
- A review of the invoice, QuickBooks and embeddings workflows.
- Hardening work against the client's reliability checklist.
- Documented workflows and data flows for future onboarding.
The work ran as an hourly engagement from mid-November to mid-December 2025 and closed with the client's five-star rating.
- n8n
- Supabase
- QuickBooks Online
- ClockShark
- Embeddings and AI agent workflows
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