OnSIP

OnSIP

Softphone & Voicemail Manager

62 ratings
22 reviews
Free

Details

  • Released
  • Updated
  • August 2, 2018
  • May 15, 2026
OnSIP screenshot #1 for iPhone
OnSIP screenshot #2 for iPhone
OnSIP screenshot #3 for iPhone
OnSIP screenshot #4 for iPhone
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About

This app extends your business phone system to your mobile device, enabling HD voice and video calls, contact monitoring, and voicemail management. Stay connected with clients and colleagues from anywhere, without needing extra hardware.

HD voice and video calls
Voicemail management
Contact availability monitoring
Call history
Remote work connectivity
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What's New in OnSIP

2.1.1

May 15, 2026

Bug fixes and stability improvements

User reviews

App is giving major issues since update

I hate to write a bad review, but feeling compelled after reading the review before me. We’ve been an OnSip customer for over 8 years and for the first time are seriously considering switching because of the disruption to how we do business. The new update to the app is the most problematic. The app has always had issues with iOS but even more so now.

-Can’t hear the incoming caller
-dropped calls while speaking and navigating to transfer
-too many screens to navigate and switch between.
-transfer button is missing 50% of the time. If it says “open OnSip” then there is no way to transfer.
-after transfer button, too many steps to find contact. Not able to enter the extension manually.
-definitely not working with 5g. Less issues when on WiFi but still problematic.

Customer support is doing their best to manage the influx of calls but I know they are frustrated as well.
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Bugs

Phone bugs of not being able to disable the app and calls to office ringing on dr’s personal cell instead of at the office persist after she uses it in the evening to check on a patient. There used to be a way to bypass that once we realized the gliche, but it seems to be gone with recent cell updates.
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Onsip app crashes

The app crashes when the phone goes to sleep, or if you close the app, or if you go to another app, and then back Onsip, it doesn’t work.

DO NOT USE THIS APP

I cannot stress enough how terrible this app is. It is extremely glitchy and unreliable. My company just switched to another service because Onsip was so disruptive to our business.

- If you are on a call and another call comes in, the app will often drop your current call
- Calling extensions within your company often doesn’t work—the app won’t let you pick up the call, or one person won’t have sound. We resorted to just calling each other’s personal cell phones
- We used to be able to do conference calls, or put a call on hold, dial a second person to request to transfer and give them details, and then transfer the call. A recent update to the app got rid of these essential functions we have been using for years. When we spoke to a customer service rep about it, they claimed that those functions never existed.
- The “do not disturb” setting on this app only works some of the time, for no discernible reason. I had to resort to completely uninstalling the app on weekends and during vacation.

Don’t waste your time. There are far better services out there.
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Onsip app crashes

The app crashes when the phone goes to sleep, or if you close the app, or if you go to another app, and then back Onsip, it doesn’t work.

FAQ

What does OnSIP do?

OnSIP brings your business phone system to your iPhone, allowing you to make and receive HD voice and video calls, monitor contact availability, and manage your voicemail. It enables seamless business communication from any location.

What are the key features of OnSIP?

Key features include HD voice and video calling, real-time contact availability monitoring, access to recent call history, and a simple interface for managing your voicemail. It provides standard business phone functionalities without requiring additional hardware.

Is OnSIP free to use?

Based on the provided information, the app itself is free to download and use. There are no in-app purchases or advertisements mentioned.

Who is OnSIP for?

This app is designed for business professionals, remote workers, and anyone who needs to maintain their business phone presence and communication capabilities while on the move or away from the office.

How does OnSIP help with remote work?

OnSIP allows you to connect with customers, partners, vendors, and coworkers from your OnSIP account on your iPhone, regardless of your location. It ensures you have access to essential business phone features, making remote work more efficient.