Validate Chat Phone Numbers in n8n with 1Lookup + OpenAI

Validate customer phone numbers in n8n—using 1Lookup + OpenAI to spot bad or risky numbers before you message them

This workflow listens to incoming chat messages, extracts a phone number, and uses an OpenAI-powered agent plus 1Lookup to confirm whether the number is active, identify its line type (mobile/landline/VoIP), and check spam/fraud risk—so your assistant can confirm the right contact or request a replacement.

What this workflow does

• Receives an incoming chat message via the n8n Chat trigger.
• Runs an OpenAI booking-style assistant conversation that requests a phone number specifically in international format (e.g., +14155550123), using chat memory.
• Validates the number with 1Lookup to determine whether it is active and to identify the line type (mobile/landline/VoIP).
• Performs a 1Lookup spam/fraud recommendation using 1Lookup’s spam check for risk guidance.
• Responds in chat: if validation fails or the recommendation indicates block, it asks for a new number; otherwise it confirms the number and clarifies whether you should expect a text (mobile) or a call (non-mobile).

Use cases

• Lead capture QA: verify phone numbers collected from chat before follow-up outreach.
• Appointment booking: reduce failed contact attempts by distinguishing mobile vs landline/VoIP.
• Risk-aware onboarding: avoid spam/fraud-prone numbers using 1Lookup’s fraud risk recommendation.
• Support and verification flows: ask for a replacement number when validation fails.

Technical details

• n8n Chat Trigger (n8nn8n-nodes-langchainchat trigger)
• OpenAI chat model (n8nn8n-nodes-langchainlm chat open ai) with chat memory (n8nn8n-nodes-langchainmemory buffer window)
• 1Lookup integration (community node @momentum-labs/n8n-nodes-1lookup): phone validation + spam check tool
• Agent orchestration (n8nn8n-nodes-langchainagent), plus a sticky note for workflow context

Ideal for n8n users and automation engineers who want reliable phone number validation and fraud-aware routing in a chat-based workflow.