Mobile Application: Your Business Phone, Anywhere You Work
📱 A Cloud PBX mobile application is an app that replaces your phone's native dialer for business calls. Instead of using your SIM card and the mobile network, it connects to your company's phone system over the internet. You make and receive calls using your office number, on the same smartphone you already carry.
This page explains how mobile apps work within a Cloud PBX setup, why they matter for businesses in Luxembourg and the Greater Region, and what to look for when evaluating one.
How the Mobile Application Works
Your smartphone already has a native dialer app. You tap a number, your SIM card connects you through the mobile network, and your personal number appears on screen. A Cloud PBX mobile app works the same way on the surface: tap, call, done. The difference is underneath. Instead of your SIM, it uses your internet connection. Instead of your personal number, it presents your business number. And instead of a basic call log, it gives you access to your full office phone system.
The app connects to your provider's servers over Wi-Fi or mobile data using VoIP (Voice over IP), meaning voice is transmitted as data over the internet rather than through a traditional phone line.
When a colleague or client calls your office number, the call rings on both your desk phone and your mobile app at the same time. You can answer on whichever device is convenient. You can also transfer calls to colleagues, access your shared company directory, set your availability status, and listen to voicemail, all from the app.
Using Voxbi as Your Mobile App
Voxbi is the mobile and desktop application for the Mixvoip Cloud PBX system. It is available on all major platforms:
- iOS — iPhone, iOS 15 or higher. Available on the App Store. TestFlight early access available.
- Android — Android 9 or higher. Available on Google Play. Beta programme available.
- Windows — Native app (v2.16), Windows 10 or higher. Includes Jabra headset integration and actionable notifications.
- macOS — Native app via the Mac App Store. macOS Ventura 13.5 or higher. Supports click-to-call from any application.
- Web browser — No installation needed. Use Voxbi directly at voxbi.team on Chrome, Edge, Brave (126+), Firefox (127+), or Safari (17.5+).
Why It Matters for Your Business
- One number, every device. Clients and colleagues always reach you on the same business number, whether you are at your desk or on the road.
- No personal number exposure. When you call out from the app, your business number appears on the recipient's screen. Your private mobile number stays private.
- Continuity during travel. Staff travelling within Luxembourg, Germany, France, and Belgium can stay reachable without incurring roaming charges on calls, provided they use Wi-Fi or a local data connection.
What to Look For
- Call quality on mobile data. Test the app on 4G/5G, not just Wi-Fi. Poor codecs or insufficient bandwidth management will degrade call quality in the field.
- Battery and background behaviour. Some apps drain battery quickly or miss incoming calls when running in the background. Check user reviews and iOS/Android compatibility notes.
- Feature parity with the desk phone. Confirm that transfer, hold, conference, and voicemail features are available in the mobile app, not just on the desktop or hardware phone.
- Native app or third-party SIP client. Most Cloud PBX providers supply their own mobile app. If yours does not, or if you manage a mixed environment, a third-party SIP softphone can connect to any VoIP system. See the toggle below for options.
📶 Connectivity and Call Quality
The mobile app relies on a stable internet connection. On Wi-Fi, call quality is typically high. On mobile data (4G or 5G), quality depends on signal strength and the codec used by your provider. Most modern Cloud PBX apps support the Opus codec, which adapts to varying bandwidth conditions and maintains acceptable quality even on weaker connections. Ask your provider which codecs the mobile app supports before committing to a plan.
🔔 Incoming Call Handling
Receiving calls reliably on a mobile app requires the app to run in the background and respond to push notifications. On iOS, Apple Push Notification Service (APNs) is used to wake the app when a call arrives. On Android, behaviour varies by manufacturer. Some phones aggressively restrict background processes to save battery, which can cause missed calls. Most enterprise-grade Cloud PBX apps provide guidance on battery optimisation settings for common Android models.
🔒 Security and Encryption
Business calls over a mobile app should be encrypted in transit. Look for providers that use SRTP (Secure Real-Time Transport Protocol) for voice encryption and TLS (Transport Layer Security) for signalling. This is particularly relevant for professions handling sensitive information, such as legal, medical, or financial services. Ask your provider for documentation on their encryption standards.
📋 User Management and Provisioning
In a Cloud PBX system, the administrator assigns each user an extension and configures their mobile app access from a central dashboard. No on-site IT visit is needed. New staff can be set up in minutes. If an employee leaves, access can be revoked immediately from the same dashboard, ensuring the business number is never tied to a personal device permanently.
🌍 Cross-Border Use in the Greater Region
For businesses operating across Luxembourg, Germany, France, and Belgium, the mobile app is particularly useful. Staff in different countries can remain on the same internal phone system, transfer calls between offices, and appear under a single company number. Calls between colleagues within the same Cloud PBX system are typically free, regardless of which country each person is physically in.
📱 Third-Party SIP Softphone Apps
If your Cloud PBX provider does not supply its own mobile app, or if you are running a self-hosted system such as Asterisk, FreePBX, or FreeSWITCH, you can use an independent SIP softphone. These apps connect to any SIP-compatible phone system and work on iOS and Android.
The most widely used options are:
Linphone — Fully open-source and free. Supports TLS, SRTP encryption, video, and messaging. Best for technically oriented users and privacy-focused setups. The interface is functional but less polished than commercial alternatives.
Zoiper — One of the most widely used SIP clients. Easy to set up with any SIP server. Available on iOS, Android, and desktop. The free version covers basic calling; encryption and additional codecs require the paid version.
Bria by CounterPath — Enterprise-grade client with HD voice, video, and XMPP support. Works with your own VoIP server. Best for businesses that need high call quality on mobile. Subscription-based pricing.
Groundwire by Acrobits — Favoured by VoIP professionals for its reliability and battery-efficient push notifications on mobile networks. Supports multiple SIP accounts and advanced codec configuration. One-time purchase (around $10).
Sipnetic — Free, lightweight, and focused on pure SIP calling for Android. Supports push notifications and encryption. Android only; no iOS version available.
These apps are provider-independent. If you are using Mixvoip Cloud PBX, the native Voxbi app is the recommended choice as it is optimised for the system and supported directly by the provider.
Frequently Asked Questions
How is the mobile app different from just using my regular phone?
Your regular phone uses a SIM card and the mobile network to make calls. The Cloud PBX mobile app uses your internet connection instead. The result feels the same: you dial a number and speak to someone. But with the app, your business number is shown instead of your personal mobile number, you can transfer calls to colleagues, and you stay connected to your company's phone system wherever you are.
Can I use the mobile app and my desk phone at the same time?
Yes. Both devices can ring simultaneously when your number is called. This is called simultaneous ring, or "find me" behaviour. You answer on whichever device picks up first, and the other stops ringing. Your provider's dashboard lets you configure which devices ring together.
Will callers see my personal mobile number when I call from the app?
No. When you make a call from the Cloud PBX mobile app, the recipient sees your business number. Your personal mobile number is not disclosed. This applies whether you are calling from Wi-Fi or mobile data.
Does the mobile app work abroad?
Yes, as long as you have an internet connection. The app uses VoIP, so it works over any Wi-Fi or mobile data connection, including when you are travelling within the EU or further afield. Standard roaming charges do not apply to the call itself, though your mobile data plan may apply if you are not on Wi-Fi.
Is the mobile app free, or does it cost extra?
This depends on the provider. Some Cloud PBX providers include mobile app access in their standard licence fee. Others charge a small monthly add-on per user. Always check whether mobile app access is included before signing a contract.
What happens if I lose or change my phone?
Because your phone number and settings are managed centrally by the Cloud PBX system, not stored on the device, you can simply install the app on a new phone and log in. Your number, voicemail, and settings are restored immediately. No number porting or SIM transfer is needed.
📅 Ready to explore Cloud PBX for your business?
Start with the provider comparisons or feature guides. If you want expert help, book a short call with a consultant.
Related Features
- Fixed Mobile Convergence — Connect your mobile and office lines under one number and one bill.
- Call Forwarding — Route calls to any device or number when you are unavailable.
- Voicemail to Email — Receive voicemail recordings as audio files in your inbox.
Learn more on the Voxbi downloads page or try Voxbi directly at voxbi.team.
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