TL;DR

Quick recommendation:

• Choose Intercom Fin if: Already using Intercom, want fastest setup, willing to pay premium
• Choose Zendesk AI if: Need traditional ticketing, omnichannel support, large team
• Choose Custom AI if: Want control over costs, need cross-platform automation, have unique workflows

Intercom vs Zendesk vs Custom AI: Customer Support Automation Comparison

AI-powered customer support is no longer optional. The question is: use a platform's native AI (Intercom Fin, Zendesk AI) or build custom automation with tools like Athenic?

This comparison helps you decide based on your team's needs, budget, and technical capabilities.

Quick Comparison

Detailed Comparison

1. AI-Powered Resolution

Intercom Fin:

• How it works: Chatbot answers customer questions using knowledge base articles
• Resolution rate: 40-50% (Intercom's published benchmarks)
• Strengths: High accuracy (trained on Intercom customer data), conversational tone, seamless handoff to humans
• Weaknesses: Requires comprehensive knowledge base, expensive per-resolution pricing

Example:

Customer: "How do I reset my password?" Fin: "I can help with that! [Provides step-by-step instructions from knowledge base] Would you like me to send a password reset link?"

Zendesk AI:

• How it works: AI agent answers via chat, email, or ticket; suggests articles to agents
• Resolution rate: 30-45% (varies by implementation)
• Strengths: Multi-channel (not just chat), integrates with traditional ticketing workflow
• Weaknesses: Lower resolution rate than Intercom Fin, requires Zendesk Suite plan (expensive)

Example:

Customer emails: "My order hasn't arrived yet" Zendesk AI: Checks order status via integration, replies "Your order shipped yesterday and will arrive tomorrow. Here's tracking: [link]"

Custom AI (via Athenic):

• How it works: AI agent monitors email/chat, queries knowledge base or APIs, drafts responses, optionally sends automatically or routes to human
• Resolution rate: 35-60% (depends on knowledge base quality and approval workflow)
• Strengths: Full control over logic, knowledge sources, escalation rules, cost at scale
• Weaknesses: Requires initial setup (2-4 weeks), you maintain knowledge base

Example:

Customer emails: "Can you send me the invoice from last month?" Athenic agent: Searches accounting system (Xero), finds invoice, attaches to reply, sends automatically (or requests human approval first)

Winner: Intercom Fin (highest resolution rate), but custom AI wins on cost at high volume

2. Knowledge Base Requirements

Intercom:

• Required: Intercom Articles (their knowledge base product)
• Cost: Included in most plans, but requires content creation
• Assessment: Fin only works with Intercom Articles, can't use external knowledge bases

Zendesk:

• Required: Zendesk Guide (their knowledge base product)
• Cost: Included in Suite plans (£55+/agent)
• Assessment: Similar to Intercom - locked into Zendesk ecosystem

Custom AI:

• Required: Any knowledge source (Notion, Confluence, Google Docs, custom docs, etc.)
• Cost: Depends on knowledge tool you already use
• Assessment: Flexible - can combine multiple sources (internal docs + product docs + past tickets)

Winner: Custom AI (most flexible)

3. Pricing

Intercom Pricing:

• Essential: £74/seat/month (includes Fin)
• Advanced: £107/seat/month
• Expert: £149/seat/month
• Fin AI: £0.99 per resolution (on top of seat cost)

Example cost (5-person support team, 1,000 AI resolutions/month):

• Seats: 5 × £74 = £370/month
• AI resolutions: 1,000 × £0.99 = £990/month
• Total: £1,360/month

Zendesk Pricing:

• Suite Team: £55/agent/month
• Suite Growth: £89/agent/month
• Suite Professional: £115/agent/month
• Zendesk AI: Usage-based (approx £0.50-£0.80 per resolution)

Example cost (5-person support team, 1,000 AI resolutions/month):

• Seats: 5 × £55 = £275/month
• AI resolutions: 1,000 × £0.65 (avg) = £650/month
• Total: £925/month

Custom AI (Athenic) Pricing:

• Athenic: £120/month (1,000 automations) or £480/month (5,000 automations)
• Email/chat tool: £0-£50/month (use existing or add SendGrid, Front, etc.)
• Knowledge base: £0-£100/month (use existing Notion, Confluence, etc.)

Example cost (5-person support team, 1,000 AI resolutions/month):

• Athenic: £120/month
• Tools: £50/month (email/chat)
• Total: £170/month

Cost comparison:

• Custom AI: £170/month (cheapest)
• Zendesk: £925/month
• Intercom: £1,360/month (most expensive)

Winner: Custom AI (8× cheaper than Intercom at 1,000 resolutions/month)

4. Setup and Implementation

Intercom Fin:

• Setup time: 2-3 days
• Requirements: Existing Intercom account, knowledge base articles written
• Process:
  1. Enable Fin in Intercom settings
  2. Configure which articles Fin can use
  3. Set confidence threshold for auto-responses
  4. Test and launch

Zendesk AI:

• Setup time: 1 week
• Requirements: Zendesk Suite plan, knowledge base content
• Process:
  1. Enable AI agent in Zendesk admin
  2. Train on knowledge base
  3. Configure channels (email, chat, social)
  4. Set escalation rules
  5. Test and launch

Custom AI (Athenic):

• Setup time: 2-4 weeks
• Requirements: Knowledge base (Notion, Confluence, etc.), email/chat tool access
• Process:
  1. Connect knowledge base to Athenic
  2. Build AI agent workflow (query knowledge base, draft response, send or escalate)
  3. Configure approval rules (auto-send for simple queries, human review for complex)
  4. Integrate with email/chat tool
  5. Test with sample inquiries
  6. Launch and monitor

Winner: Intercom (fastest), but custom AI provides more control despite longer setup

5. Escalation and Human Handoff

Intercom Fin:

• Escalation: Seamless handoff to Intercom inbox
• Agent view: Fin conversation history visible, agent continues thread
• Strengths: Smooth experience (customers don't need to repeat themselves)

Zendesk AI:

• Escalation: Creates Zendesk ticket, routes to appropriate team
• Agent view: AI transcript attached to ticket
• Strengths: Integrates with existing ticketing workflow

Custom AI (Athenic):

• Escalation: Flexible (Slack notification, email to support team, create ticket in Zendesk/Intercom)
• Agent view: Depends on your setup (can integrate with any tool)
• Strengths: Full control over escalation logic and destinations

Winner: Intercom/Zendesk (seamless native handoff), but custom AI offers flexibility

Use Case Recommendations

When to Choose Intercom Fin

Best for:

• B2B SaaS companies already using Intercom
• High-touch, consultative support (low to medium volume)
• Teams prioritizing customer experience over cost
• Fast setup requirement (need AI support in days, not weeks)

Example profile:

• 200 support inquiries/week
• 5-person support team
• Already paying for Intercom
• Want 40-50% auto-resolution to reduce load

Annual cost: ~£16,320

When to Choose Zendesk AI

Best for:

• High-volume, multi-channel support operations
• Teams using traditional ticketing workflows
• Companies needing phone, SMS, social media support (not just chat)
• Enterprises with complex routing and SLA requirements

Example profile:

• 2,000 support inquiries/week
• 15-person support team across email, phone, chat
• Need ticketing, SLA tracking, multi-brand support
• Want 30-45% auto-resolution

Annual cost: ~£19,800 (agents) + £7,800 (AI resolutions) = ~£27,600

When to Choose Custom AI (Athenic)

Best for:

• Cost-conscious teams with high inquiry volumes
• Companies wanting control over AI logic and knowledge sources
• Teams comfortable with 2-4 week setup
• Organizations needing cross-platform automation (not just support)

Example profile:

• 1,000 support inquiries/week
• 8-person support team
• Using Front or Gmail for support (not Intercom/Zendesk)
• Want 50%+ auto-resolution at low cost

Annual cost: £480/month × 12 = ~£5,760 (12× cheaper than Intercom)

Hybrid Approaches

Some teams use Intercom/Zendesk + Custom AI:

Example: Zendesk + Athenic

• Zendesk: Ticketing system, agent workspace, phone support
• Athenic: AI layer handling email auto-responses, knowledge base queries, ticket enrichment
• Benefit: Keep familiar Zendesk workflow, add custom AI automation at lower cost than Zendesk AI

Cost comparison:

• Zendesk + Zendesk AI: £925/month
• Zendesk + Athenic: £275 (Zendesk seats) + £120 (Athenic) = £395/month (-57% cost)

Migration Considerations

Intercom → Zendesk:

• Effort: High (different ticketing paradigm)
• Timeline: 6-8 weeks
• Loss: Chat-first workflow, some automation logic

Zendesk → Intercom:

• Effort: High (ticket history migration complex)
• Timeline: 6-8 weeks
• Loss: Traditional ticketing, phone support integration

Either → Custom AI:

• Not a migration (custom AI complements existing tool)
• Keep Intercom/Zendesk for agent workspace
• Add Athenic for AI automation layer

Final Verdict

For most B2B companies, we recommend:

• <500 inquiries/week: Intercom Fin (fast setup, good experience, cost manageable)
• 500-2,000 inquiries/week: Custom AI (Athenic) with Front or Gmail (cost savings significant)
• 2,000+ inquiries/week: Zendesk + Custom AI hybrid (Zendesk for ticketing, Athenic for AI layer)

Cost becomes deciding factor at scale:

• 1,000 inquiries/month: Custom AI saves £1,190/month vs Intercom (£14,280/year)
• 5,000 inquiries/month: Custom AI saves £4,555/month vs Intercom (£54,660/year)

Using Intercom or Zendesk? Athenic can add an AI automation layer on top - reducing costs while maintaining your existing support workflow. See support automation →

Want to build custom AI support? Athenic provides pre-built templates for email/chat support automation, knowledge base integration, and escalation workflows. Start free trial →

Related reading:

• Email Response Automation: Customer Support Guide
• Customer Success Automation with AI Agents
• Athenic vs Zapier vs Make.com: Automation Comparison