Recover failed Stripe payments with AI emails (by FlyCode)
⚙️ Automated Stripe Failed Payment Recovery (with Postmark + AI Email Generator)
Recover failed Stripe subscription payments with AI-personalized emails sent via Postmark.
📝 Template Description
Recover failed subscription payments automatically with Stripe, Postmark, and AI.
This workflow listens for Stripe invoice.payment_failed webhooks, checks that the event is related to an auto-charged subscription, and then automatically sends a personalized email (generated with AI) to the customer. The email is polite, branded, but also urgent — encouraging the customer to pay quickly and avoid service cancellation.
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🛠️ How it works
📣 Webhook
Listens for Stripe webhook events. Make sure to connect it in your Stripe dashboard (see setup below).
🧹 Filter (Guard)
Ensures the event is indeed an invoice event and filters out unrelated webhooks.
💡 Code Node
Extracts useful fields (firstName, lastName, customer email, amount, currency, invoice number, hosted invoice URL, subscription description, account name).
✅ If Node
Verifies that:
Event type = invoice.payment_failed
Billing reason = subscription_cycle
Collection method = charge_automatically
👉 This ensures only recurring subscription invoices with auto-payment are processed.
🤖 AI Agent + OpenAI
Generates a ready-to-send email JSON (to, subject, HTML body) using the extracted Stripe data.
✍️ You can customize the prompt here to match your brand’s tone of voice and style.
🧩 Code Parser
Parses the AI model’s JSON output into fields (toemail, emailsubject, email_body).
📧 HTTP Request (Postmark)
Sends the email using Postmark’s API.
You’ll need your own Postmark Server Token, From address, and Message Stream.
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🚀 Setup Instructions
Stripe Webhook
Go to Stripe Dashboard → Developers → Webhooks.
Click + Add endpoint.
Use your n8n Webhook URL (from the Webhook node) as the endpoint.
Select event type: invoice.payment_failed.
Save and deploy.
👉 Example docs: Stripe: Listen to events with webhooks.
Disable Stripe’s Default Failed Payment Emails
In Stripe, go to Billing → Settings → Customer emails → Manage failed payments.
Turn off “Failed payment” emails under the Revenue Recovery section.
This prevents customers from receiving duplicate or conflicting emails.
Postmark Setup
Create a Postmark account.
Add a Server and copy the Server API Token.
In n8n, add Postmark credentials with this token.
Configure:
From = your verified sending email (must be verified in Postmark).
MessageStream = typically "outbound" (or any custom stream you set up).
Docs: Postmark API overview.
OpenAI Setup
Add your OpenAI credentials in n8n.
Attach them to the OpenAI Chat Model node.
You can modify the prompt in the AI Agent node to fit your company’s style.
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✨ Customization Tips
Update the AI prompt with your brand’s tone of voice (friendly, formal, playful, etc.).
Adjust the HTML email design inside the prompt (button colors, footer, etc.).
Add extra guard conditions (e.g., only trigger if invoice_amount > 0).
Change the sending service: replace Postmark with Gmail, SMTP, or another provider.
💬 Or talk to our Billing Recovery Experts at flycode.com for hands-on help.
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✅ Outcome
Whenever a customer’s subscription payment fails, this workflow:
Detects it instantly via Stripe
Generates a polite but urgent recovery email
Sends it automatically via Postmark
Result: Fewer cancellations, higher recovered revenue, and a smoother customer experience. 💸💌
By FlyCode