Google Sheets Invoice Automation with AI: Step-by-Step
- How the flow works — overview
- Step 1 — Set up your Zenphi account and trigger
- Step 2 — Add an AI model for data extraction
- Step 3 — Extract and test invoice fields
- Step 4 — Write extracted fields to Google Sheets
- Step 5 — Route by confidence score
- Step 6 — Send for payment and notify the supplier
- Test and publish your flow
- Frequently asked questions
How the automated invoice flow works
Processing invoices manually is slow, error-prone, and hard to scale. On average, it takes businesses 1–2 weeks to process a single invoice, with a typical accountant handling around 40 per day. Late payments, lost invoices, and data entry errors are the predictable result. Automation removes the manual coordination — not the oversight.
Using Zenphi's AI workflow automation, you can build a flow that captures invoices the moment they arrive, extracts the fields you care about using an AI model of your choice, stores everything in Google Sheets, and routes only the invoices that need human attention to your accounts payable team. Everything else proceeds to payment automatically.
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How to build the invoice automation flow
Create your free Zenphi account, then open the flow builder to start your first automated flow. In Zenphi, a flow is the entire automated process — a trigger that starts it, followed by the actions that represent each step.
For invoices, you have two trigger options:
- Google Drive trigger — fires whenever a new invoice is added to a chosen Drive folder. Best for teams that receive scanned or uploaded PDFs.
- Gmail trigger — fires when an invoice arrives by email. Best when suppliers send invoices directly to an inbox.
Add a text agent step to your flow. Zenphi gives you access to three AI providers on all pricing tiers — all integrations are pre-built, no API keys to configure:
Once added, define which fields to extract — vendor name, invoice number, date, line items, total, currency, payment terms, and so on. Configure the output format so downstream steps can read the values as individual tokens.
Watch the short video walkthrough for configuring an AI model for data extraction:
Before proceeding, save your flow and perform a test run. Press Test Run, select an invoice document from Google Drive, then open the Output tab inside the AI model step. If all fields are extracted correctly and the confidence scores look right, the model is ready.
This is also where you confirm what confidence score threshold you're comfortable with — the score is visible per-field in the output and will drive the routing logic in Step 5.
Use the Add Row action to write extracted invoice data to your chosen Google Sheet. Map each AI model output token to the corresponding column — vendor, invoice number, amount, date, status, and so on.
Then add a Get Item Information action to retrieve the view link for the Google Sheet row. This link can be included in review emails so the accounts payable team can open the record directly without searching for it — a core part of efficient Google Sheets invoice automation.
Add an If Condition action. Configure it to read the Confidence Score token from the AI extraction step. Set the condition: Confidence Score equal to or less than 0.80.
In the True branch, use an Update Row action to set the Google Sheet status to "Sent for Manual Review." Then use Assign Task to send a review email to the accounts payable team — include the invoice as an attachment and use the token picker (chain icon) to pull extracted values directly into the email body. Set two decision options: Approve and Reject.
This lets the reviewer approve or reject without leaving their inbox, comparing the email body against the attached invoice. The Assign Task action also lets you configure automatic reminders so nothing sits unreviewed.
Once manual review is approved — or bypassed entirely because the confidence score was high — use a Read Row action to fetch the most current invoice data from Google Sheets. This ensures any corrections made during review are picked up before the payment task is sent.
Use Assign Task again to notify the payments team with the invoice details. Once that task is completed, use Send Email (Gmail) to notify the supplier that payment has been processed.
Add a Format Date/Time action to include the exact payment completion timestamp in the supplier email — you control how the date and time is displayed.
Test and publish your flow
Once you've built and reviewed each step, run a final end-to-end test with a real invoice. Check that the fields are extracted correctly, the Google Sheet row is populated, the confidence routing works as expected, and both the review email and supplier notification send correctly.
When satisfied, press Save and Publish. Your flow is now live — from that point on, every invoice that lands in your selected Drive folder or Gmail trigger inbox will be captured, extracted, logged, routed, and processed automatically.
You can add or remove steps to fit your exact process. Some teams add a three-way matching step to verify invoices against POs and delivery notes before the confidence check. Others add a Slack or Google Chat notification at the manual review stage. The flow structure stays the same — the steps inside it are yours to configure.
For a broader look at what's possible with invoice and accounts payable automation, see accounts payable and invoice processing automation.
Frequently asked questions
Common questions about building the invoice automation flow in Zenphi.
After creating your free Zenphi account, you build a flow that starts with a trigger. Use the Google Drive trigger to kick off the flow whenever a new invoice is added to a chosen Drive folder, or use the Gmail trigger if invoices arrive via email. From there, the flow automatically captures and processes each invoice — no manual action required.
After the AI model runs, the Confidence Score is available as a variable in the Output tab. By adding an If Condition step, you can configure it to read the confidence score and branch the flow accordingly. If the score is above 0.80, the invoice proceeds straight to payment. If it's at or below 0.80, it's routed to the accounts payable team for review before any payment action is taken.
The Add Row action writes the extracted fields to your chosen Google Sheet, mapping each AI model output token to the corresponding column for centralized tracking and reporting. A Get Item Information action then retrieves a direct view link to that row, which can be included in review emails so the accounts payable team can open the record immediately without searching for it.
Once manual review is completed — or bypassed entirely because the confidence score was high — a Read Row action fetches the latest invoice data from Google Sheets to ensure any corrections are picked up. An Assign Task action sends the payment details to the payments team. Once completed, Send Email (Gmail) notifies the supplier. The Format Date/Time action can include the exact payment completion time in the email. This approach also applies to two-way invoice matching.
Start automating your invoice processing — free
Zenphi is free to start. Build your first invoice automation flow today — no developer, no credit card, no per-user fees. Or book a session and our team will build it with your actual invoices and process logic.
