Automate Stripe Invoice Payments with HubSpot and Slack via n8n

Opening Problem Statement

Meet Sarah, the accounts manager at a growing SaaS company. Every month, Sarah’s team processes hundreds of Stripe invoice payments. Each payment requires her to manually update corresponding deals in HubSpot to mark them as paid and notify the accounts and sales teams in Slack. This manual process not only wastes several hours weekly but also leads to frequent errors such as missed updates or notifications. These delays affect the finance team’s ability to track incoming revenue accurately and disrupt sales follow-ups.

Sarah estimates that manually handling this process takes over 5 hours per week with a 10% error rate, costing her company both time and revenue insight. She needs a reliable automated method to sync Stripe payments with HubSpot deals and keep her team informed instantly without lifting a finger.

What This Automation Does

This n8n workflow provides an elegant, hands-off solution to Sarah’s problem. Here’s what happens when it runs:

• Automatically listens for successful Stripe invoice payments via the Stripe Trigger node.
• Checks if the payment includes a Purchase Order (PO) number to identify the related HubSpot deal.
• Searches HubSpot for a matching deal by PO number to ensure the payment is tied to the right customer record.
• Updates the HubSpot deal’s custom property to “Paid” automatically upon successful matching.
• Sends detailed Slack notifications to the accounts team about each payment’s status—whether processed, missing PO number, or deal not found.
• Helps prevent manual errors and speeds up financial tracking by automating key tasks that were previously done manually.

This workflow can save Sarah and her team at least 5 hours weekly, drastically lower errors, and improve real-time payment visibility across teams.

Prerequisites ⚙️

• n8n account with access to create workflows.
• Stripe account with API credentials set up in n8n for payment webhook listening.
• HubSpot account authorized with OAuth2 for deal searching and updating.
• Slack workspace and API token to send channel notifications.
• Some familiarity with creating and editing nodes in n8n.

If you want to run this on your own servers instead of cloud-hosted n8n, consider using Hostinger for hassle-free self-hosting.

Step-by-Step Guide ✏️

Step 1: Set up Stripe Trigger Node for Invoice Payment Events

Navigate to your n8n editor. Click + Add Node → Choose Stripe Trigger. In the parameters panel:

• Select the event invoice.payment_succeeded.
• Assign your Stripe API credentials.
• This node listens for every successful invoice payment Stripe processes.

Outcome: Workflow triggers whenever a customer pays an invoice.

Common mistake: Forgetting to select correct event or connect Stripe API credentials properly.

Step 2: Add an If Node to Check for PO Number Presence

Click + Add Node → Choose If node. Configure condition:

• Set condition type to String,
• Value 1 to the PO number JSON path: {{$json["data"]["object"]["custom_fields"]}}
• Operation: is empty

This check verifies if the Stripe invoice included a PO number.

Outcome: Directs the workflow to take different branches depending on presence of PO number.

Common mistake: Incorrectly referencing the PO number path leading to wrong condition outcomes.

Step 3: Send Slack Notification if No PO Number Found

If no PO number, flow branches here. Add a Slack node connected to the If node’s true output:

• Configure the node to post a message in your team-accounts channel.
• Message text: :x: Stripe Payment with no PO Number :x:
• Add message fields including amount, currency, customer name/email, and transaction ID extracted from the Stripe webhook data.
• Connect Slack API credentials.

Outcome: Team receives immediate alert about payments missing PO numbers, allowing follow-up.

Common mistake: Missing Slack API token or incorrect channel name.

Step 4: Search HubSpot for Deal Based on PO Number

When PO number exists, add a HubSpot node with operation search. Set filter:

• Property to search on: po_number
• Value: PO number value from Stripe webhook JSON path {{$json["data"]["object"]["custom_fields"][0]["value"]}}
• Connect HubSpot OAuth credentials.

This node finds the related deal in HubSpot to update.

Outcome: Workflow gathers deal info needed to mark it paid later.

Common mistake: Misconfiguring filter property or JSON paths causing no results.

Step 5: Use If Node to Check if HubSpot Deal Was Found

Add another If node immediately after the search node:

• Check if {{$json["id"]}} is empty.
• If empty, no deal was found matching the PO number.

Outcome: Routes workflow either to update deal or send error notification.

Common mistake: Incorrect JSON path in condition can cause false positives.

Step 6: Send Slack Message If No Deal Found

Connect the true branch of the previous If node to a Slack node:

• Customize a message alerting the team that no deal was found for the payment, including details like amount, customer, PO number, and transaction ID.
• Send message to team-accounts channel.

Outcome: Helps identify payments that need manual attention.

Common mistake: Not filling Slack message fields properly leading to missing info.

Step 7: Update the HubSpot Deal When Found

On the false branch (deal found), add a HubSpot node to update the deal:

• Operation: update
• Deal ID: Set dynamically to {{$json["id"]}} from search node output.
• Set custom property paid to Yes.
• Ensure OAuth credentials are connected.

Outcome: Marks deal as paid immediately when payment is confirmed.

Common mistake: Not mapping deal ID correctly resulting in no update.

Step 8: Notify the Team in Slack About Payment Confirmation

Connect the output of the update node to a Slack node to inform the team of the successful update:

• Message text: :sparkles: An invoice has been paid :sparkles:
• Include detailed fields from Stripe payload such as amount, currency, customer name/email, PO number, and transaction ID.
• Post in your team’s accounting Slack channel.

Outcome: Your team has real-time visibility into payments and deal status.

Common mistake: Forgetting to link the Slack node to the update node output or missing fields.

Customizations ✏️

• Change Slack Channel: In any Slack node, update the channel parameter to notify a different team or private group.
• Add More HubSpot Properties: In the Update Deal to Paid node, include other fields like last payment date or transaction ID for richer deal tracking.
• Filter by Currency: Add another If node before deal update to verify currency type (e.g., only update deals if payment is in USD).
• Enhance Slack Messages: Include clickable links to HubSpot deals or Stripe invoice URLs for quick access.
• Add Email Notifications: Insert Email nodes to parallel Slack alerts for broader notification reach.

Troubleshooting 🔧

Problem: “Workflow not triggering on Stripe payment”

Cause: Stripe webhook not properly configured or endpoint URL not registered with Stripe.

Solution: Verify Stripe webhook configuration matches the URL generated by the Stripe Trigger node in n8n. Recreate webhook in Stripe Dashboard if needed.

Problem: “No deal found even though PO number exists”

Cause: HubSpot search filter property name or PO number format does not match actual deal data.

Solution: Double-check property name po_number in HubSpot and confirm PO numbers in deals exactly match those sent from Stripe invoices.

Problem: “Slack messages missing data fields”

Cause: Incorrect JSON paths used in Slack node message fields.

Solution: Use the expression editor in Slack node to insert correct paths from the previous nodes. Test with live payloads.

Pre-Production Checklist ✅

• Ensure Stripe webhook triggers are active and firing as expected.
• Test HubSpot deal searches with sample PO numbers matching existing deals.
• Confirm Slack API token has the necessary permissions to post in designated channels.
• Run tests using Stripe’s test mode payments to simulate the entire workflow end-to-end.
• Backup existing HubSpot deal data before deploying updates, especially for production environments.

Deployment Guide

Once fully tested, activate your workflow by toggling the active switch in n8n.

Monitor the workflow execution log in n8n for any errors during the initial runs.

Regularly review Slack channels and HubSpot for accurate payment status updates.

FAQs

• Can I use a different CRM instead of HubSpot? Yes, you can replace the HubSpot nodes with nodes configured for other CRMs, but you’ll need to adjust search and update operations accordingly.
• Does this workflow consume Stripe API credits? This workflow uses Stripe webhooks, which do not consume API call credits since event delivery is pushed, not pulled.
• Is my payment data secure? n8n uses OAuth2 and API key credentials that you control. Keep your credentials safe and limit access to your workflow environment.
• Can it handle high payment volumes? Yes, but you may want to scale n8n resources if you process thousands of payments per minute.

Conclusion

By setting up this n8n workflow, Sarah automated the tedious process of marking Stripe invoice payments as paid in HubSpot and instantly notifying her team in Slack. This eliminated hours of manual data entry, reduced errors, and significantly improved payment tracking transparency. You’ve now built a resilient payment monitoring system that keeps your sales and finance teams aligned effortlessly.

Next steps could be expanding automation to issue receipts or refund notifications, integrating detailed financial reports in Google Sheets, or enhancing deal tracking with payment timelines.

With this foundation, you’re well-equipped to keep scaling your payment workflows with confidence and ease!