OnSIP
OnSIP · Sunnyvale, California, United States · founded 2004
What it is
OnSIP is a business phone system with mobile and desktop apps, web access, and multiple business numbers. It includes an auto attendant, custom call routing, and voicemail transcription. Its free plan supports up to 100 users and unlimited extensions, and includes Zendesk, HubSpot, and Odoo integrations. Free SIP accounts cannot dial regular phone numbers; paid plans offer SIP-to-PSTN gateway service. The browser softphone works in Chrome, Firefox, and Opera, and a SIP address can be active on up to 10 devices. Softphone apps provide end-to-end encryption, with encryption also available for desk phones. The Admin Portal supports setup, feature edits, payment and contact management, and invoices. OnSIP offers month-to-month contracts, with payment based on users and features. Pricing lists a free plan and paid service from $18.95/user/mo, with a 30-day trial. It is available for Android, iOS, Mac, Windows, and web.
For and against
For
- Free plan supports up to 100 users and unlimited extensions.
- Custom call routing and an auto attendant are included.
- Voicemail transcription is available.
- Softphone apps provide end-to-end encryption.
- Month-to-month contracts are available.
Against
- Free SIP accounts cannot dial regular phone numbers.
- Unlimited plan requires a minimum of five users.
- Web and desktop video conferences support up to five people.
The verdict
OnSIP combines business calling features, administration tools, and apps across desktop and mobile platforms. Check the plan details carefully, particularly the free plan's restriction on calling regular phone numbers.
Who it suits
OnSIP suits businesses that need a configurable phone system with multiple business numbers and call routing. Its free plan may suit teams that do not need to dial regular phone numbers from free SIP accounts.
Plans and prices
Free Plan
100 users
Read 28 Sep 2026 · onsip.com
Unlimited
5 users minimum · 250 SMS/MMS per account
Read 28 Sep 2026 · onsip.com
Basic
3 auto attendants · 3 ring groups · 5 voicemail boxes · 1 call recording user
Read 28 Sep 2026 · onsip.com
Pay-as-you-go
Read 28 Sep 2026 · onsip.com
On the record
- Admin tools
- The Admin Portal supports setup, real-time feature edits, payment and contact management, and invoices.onsip.com · read 28 Sep 2026
- Auto attendant
- Yesonsip.com · read 22 Sep 2026
- Browser support
- The browser softphone is available in Chrome, Firefox, and Opera.onsip.com · read 28 Sep 2026
- Business numbers
- multipleonsip.com · read 22 Sep 2026
- Call routing
- customonsip.com · read 22 Sep 2026
- Audio conference limit
- Audio conference suites support up to 15 simultaneous callers.onsip.com · read 28 Sep 2026
- Business customers
- OnSIP says it is trusted by more than 150,000 businesses.onsip.com · read 28 Sep 2026
- Desktop and mobile apps
- Yesonsip.com · read 22 Sep 2026
- Device registrations
- A SIP address can have active registrations on up to 10 devices.onsip.com · read 28 Sep 2026
- Call encryption
- Softphone apps provide end-to-end encryption, with encryption also available for desk phones.onsip.com · read 28 Sep 2026
- Free calling limit
- Free SIP accounts cannot dial regular phone numbers; paid plans offer SIP-to-PSTN gateway service.onsip.com · read 28 Sep 2026
- Free integrations
- The free plan includes Zendesk, HubSpot, and Odoo integrations.onsip.com · read 28 Sep 2026
- Free plan limits
- The free plan supports up to 100 users and unlimited extensions.onsip.com · read 28 Sep 2026
- HIPAA support
- The platform can be used by businesses to comply with HIPAA obligations.onsip.com · read 28 Sep 2026
- Included users
- 5onsip.com · read 22 Sep 2026
- CRM integrations
- Available integrations include HubSpot, Odoo, Zendesk, and an Open API.onsip.com · read 28 Sep 2026
- Knowledge base
- The knowledge base contains setup articles, instructions, and video walkthroughs built over 20 years.onsip.com · read 28 Sep 2026
- Billing model
- Month-to-month contracts are available, with payment based on needed users and features.onsip.com · read 28 Sep 2026
