Vonage Business is UCaaS + CPaaS over softphone. Kelir is UCaaS over cellular.
Vonage's strength is the combined UCaaS + CPaaS (developer API) story — you can build custom communications workflows on Vonage's platform. Kelir's UCaaS feature depth is comparable for the routing primitives; Kelir's CPaaS-equivalent (the public API) is on the Phase 3 roadmap. Choose Vonage if you need API-driven custom workflows today; choose Kelir for cellular delivery and the SMB UCaaS use case.
Vonage Business Communications (VBC) is Vonage's UCaaS product: auto-attendant, multi-level IVR, hunt groups, departments, call recording, voicemail with transcripts, analytics, CRM integrations — comparable surface to Kelir at the routing layer. Vonage's distinguishing strength is the combined UCaaS + CPaaS (developer-API) story — you can build custom messaging, voice, and video workflows on Vonage APIs alongside the UCaaS deployment. Kelir delivers the same UCaaS surface on real cellular eSIM lines (vs Vonage's softphone) and ships the public API in Phase 3. Pick Vonage if you need today's API depth for custom integrations; pick Kelir if cellular reliability and the 2FA SMS deliverability story matter more than CPaaS depth.
How they compare.
| Compared | Vonage Business | Kelir |
|---|---|---|
| Delivery model | ||
| Voice transport | Softphone (Wi-Fi / mobile data) | Cellular VoLTE |
| Where the call rings | Vonage Business app | Native dialer |
| App must be open | Yes | No |
| Works without internet | ||
| 2FA SMS reliable | Limited (virtual) | |
| UCaaS routing | ||
| Auto-attendant | ||
| Multi-level IVR | 2–4 levels by tier | |
| Hunt groups | ||
| Departments | ||
| Call queuing | ||
| CPaaS / developer platform | ||
| Public API for voice | Phase 3 | |
| Public API for SMS | Phase 3 | |
| Public API for video | ||
| Webhooks | Team Pro | |
| Voicemail & analytics | ||
| Voicemail transcripts | Every plan | |
| Call recording | ||
| Configurable retention | Higher tier | Up to 7y on Pro |
| CRM integrations | Team Pro | |
| Built-in video conferencing | ||
Vonage Business information sourced from www.vonage.com/business on 2026-05-05. Plans and prices change; check the source for the current state.
- Combined UCaaS + CPaaS (developer API) on one platform — build custom voice, SMS, and video workflows on Vonage APIs.
- Mature CPaaS — global SMS/voice APIs used by enterprise customers (Airbnb, Wayfair, others) for transactional communications at scale.
- Mid-market UCaaS deployments with developer-led customizations.
- Long-running platform with deep international voice + SMS reach.
- Built-in video and team-messaging in the UCaaS bundle.
- Real cellular delivery — UCaaS routing on a cellular eSIM line, not a softphone.
- 2FA SMS deliverability — every line is a real US cellular number, accepted by banks and payment platforms.
- Mobile-first / field-based teams — CarPlay routing, lock-screen rings, native dialer.
- Simpler SMB / lower-mid-market UCaaS use case without API-platform overhead.
- Lower per-seat cost at the entry tier.
- Faster time-to-deploy for non-developer-led teams.
Side-by-side, USD.
- MobileMobile-only UCaaS, basic IVR~$20/seatper month, USD
- PremiumAdds desktop client, multi-level auto-attendant, CRM~$30/seatper month, USD
- AdvancedAdds call recording, visual voicemail~$40/seatper month, USD
- SoloSingle-user UCaaS surface$24.99per month, USD
- Team StarterMulti-user PBX, 2–50 seats$29.99per seat / month
- Team ProCRM, analytics, audit log, retention$39.99per seat / month
Who should pick which?
You need CPaaS + UCaaS together — public APIs for custom voice/SMS/video workflows alongside the UCaaS deployment. Or you need built-in video conferencing on the same platform.
You're a 2–50 person team wanting UCaaS-tier routing on real cellular delivery, no softphone failure modes, and don't need the CPaaS layer today. Mobile / field reliability and 2FA SMS deliverability are operational requirements.
Vonage Business is UCaaS-with-CPaaS — full developer-API depth for teams building custom workflows on top of UCaaS. Kelir is UCaaS-on-cellular for SMB / lower-mid-market teams who want UCaaS routing without softphone delivery and don't need the CPaaS layer. Different fits for different teams; the public-API gap on Kelir closes when Phase 3 ships.
Common questions
If you're building custom voice/SMS/video workflows on top of your UCaaS deployment — typically engineering-led teams with specific integration requirements not covered by standard CRM connectors — yes. Vonage's CPaaS is mature and proven at scale (Airbnb, Wayfair, etc.). Kelir's public API is on the Phase 3 roadmap; until it ships, custom-workflow customers should pick Vonage. For teams that just want standard CRM-connected UCaaS, the API depth doesn't matter.
Vonage Business Communications includes video meetings (Vonage Meetings) in the UCaaS bundle. Kelir is voice + SMS focused — no video. Most Kelir customers use Zoom, Google Meet, or Microsoft Teams for video and don't want their video tied to their phone vendor. If single-vendor consolidation matters, Vonage's bundled video is an advantage; otherwise it's a non-issue.
For straight business SMS use cases (appointment reminders, customer two-way threads, transactional confirmations), Kelir's SMS is comparable — A2P 10DLC pre-registered, real cellular delivery, MMS support. For high-volume SMS-as-a-service use cases (sending millions of SMS through APIs to consumers), Vonage's CPaaS is purpose-built for that and Kelir isn't. Different SMS use cases.
Yes — same general migration playbook as RingCentral or 8x8. 1–2 week timeline for a 5–25 seat team. Number porting via FCC rules. Routing config rebuild on Kelir surfaces. CRM integration reconnects via OAuth. See /use-cases/migrating-from-ringcentral for the structurally-identical playbook.
Vonage Premium ~$30/seat vs Kelir Team Starter $29.99/seat — comparable. Vonage Advanced ~$40/seat vs Kelir Team Pro $39.99/seat — comparable. The cost differentiator at total-cost-of-communication: Kelir's cellular eSIM means each user's work calls run on their phone's cellular line (no separate mobile plan needed for work); Vonage softphone users typically maintain a separate personal cell.
Yes — Vonage's routing surface is comparable to Kelir's at the entry tier. Both ship multi-level IVR, hunt groups, departments, call queuing, recording, analytics. Functional parity is high in the 2–50 seat UCaaS range.