n8n Warranty Registration Workflow: Sheets + GoHighLevel GPT-4o Reminders

Automatically register warranties and send daily service reminders with n8n + Google Sheets + GoHighLevel

This n8n workflow captures warranty registrations from an n8n Form or a webhook, stores them in Google Sheets, upserts the buyer into GoHighLevel, sends a welcome SMS and HTML warranty certificate, and then runs daily at 9:30 AM to generate and deliver OpenAI-written service and warranty reminders.

What this workflow does

• Receives warranty registrations via a hosted n8n Form trigger or a DMS/POS webhook.
• Normalizes and validates data, calculating warranty end and next service dates.
• Prevents duplicates by checking the Google Sheets Warranty Registry and filtering out duplicate serial/VIN numbers.
• Creates/updates CRM records in GoHighLevel by upserting the customer as a contact with tags and notes.
• Saves warranty details to Google Sheets by appending a registry row for each eligible registration.
• Sends welcome communications through GoHighLevel Conversations, including a welcome SMS and an HTML warranty certificate email.
• Runs daily reminder logic to determine whether each registration is service-due, overdue, or nearing warranty expiry.
• Drafts reminder content with OpenAI (gpt-4o-mini) and sends reminders via GoHighLevel, then updates reminder stage fields in Google Sheets.
• Tracks service/renewal cycles: when a new paid service or warranty renewal starts, it creates a GoHighLevel opportunity and saves the opportunity ID back to the matching registry row.

Use cases

• Warranty registration for businesses using n8n forms or POS/DMS webhook submissions.
• Automated customer onboarding: SMS welcome + HTML warranty certificate email.
• Ongoing retention: daily service and warranty expiry reminders written with OpenAI and delivered through GoHighLevel.

Technical details

• Workflow nodes/tools: if, set, code, webhook, sticky note, form trigger.
• Integrations: Google Sheets (Warranty Registry), GoHighLevel (contacts, conversations, opportunities), OpenAI (gpt-4o-mini).
• Schedule: daily at 9:30 AM.