Technology

What Is a Softphone? How It Works and Why Teams Use It

A softphone is a software application that makes and receives VoIP calls on any internet-connected device — no physical handset required.

What Is a Softphone?

A softphone is a software application that enables voice calls over an internet connection using VoIP (Voice over Internet Protocol). It runs on a computer, smartphone, or tablet and replicates the functionality of a physical desk phone in software form — including dialling, answering, hold, mute, transfer, conferencing, and voicemail.

Unlike a traditional desk phone, a softphone does not require any dedicated telephony hardware. It uses the device's built-in audio hardware (microphone and speakers or headset) and an internet connection to send and receive calls. For businesses that have moved to cloud phone systems, softphones are often the primary or only endpoint their employees need.

Softphones can be standalone applications or integrated into broader communication platforms — unified communications suites, contact center software, or CRM systems. In all cases, the underlying mechanism is the same: VoIP signalling and media transport over IP.

How Softphones Work

Most softphones use the SIP (Session Initiation Protocol) standard for call signalling. SIP is a text-based protocol that handles the setup, modification, and teardown of communication sessions. When you make a call from a softphone, here is what happens at a high level:

  1. Registration. When the softphone starts, it registers with a SIP server (hosted by your VoIP provider or your own PBX). Registration links your extension or phone number to the softphone's current IP address, so incoming calls know where to reach you.
  2. Call initiation. When you dial a number, the softphone sends a SIP INVITE message to the SIP server. The server routes the call — either to another extension on the same platform, or out through a SIP trunk to the PSTN for calls to landlines and mobile numbers.
  3. Media negotiation. SIP negotiates the audio codec — the compression format used for the voice data — between the two endpoints. Common codecs include G.711 (uncompressed, high quality, higher bandwidth), G.722 (HD audio), and G.729 (compressed, lower bandwidth). The selection affects both call quality and bandwidth consumption.
  4. Audio transport. Once the call is established, voice data flows directly between endpoints using RTP (Real-time Transport Protocol), typically over UDP. The SIP server is no longer in the media path — it only handled the signalling.
  5. Call termination. When either party hangs up, a SIP BYE message is sent, and the session is closed.

For a broader explanation of how SIP-based communication works in a business context, see our guide on what is SIP trunking.

Softphone vs Desk Phone vs Mobile App

Businesses deploying a cloud phone system typically have three endpoint options: a hardware IP desk phone, a softphone application on a computer, or a mobile VoIP app. Each has different trade-offs:

  • Desk phone (IP phone). A dedicated piece of hardware with a physical handset, keypad, and screen. Requires Power over Ethernet (PoE) or an external power adaptor. Delivers a familiar user experience, particularly in office environments where staff handle high call volumes. Does not travel with the user. Requires a physical provisioning process for each device.
  • Softphone (desktop app). Runs on a computer — laptop or desktop. No dedicated hardware required. The user interacts via keyboard, mouse, and headset. Offers tight integration with other applications running on the same machine, such as CRM or helpdesk software. Travels with the laptop, making it ideal for hybrid and remote workers. Audio quality depends on the headset and internet connection.
  • Mobile VoIP app (softphone on smartphone). The same softphone experience on a mobile device. Useful for field staff, travelling employees, or as a secondary endpoint. Can receive business calls on a mobile number registered to the platform, keeping personal and professional calls separate. Audio quality varies with mobile data connectivity.

Many organisations use all three in combination: desk phones for receptionists and high-volume call center agents, softphones for office-based staff on computers, and mobile apps for remote or field workers. A cloud business phone platform supports all three endpoint types from the same administration interface.

Key Features to Look For

Not all softphones offer the same feature set. When evaluating a softphone — either as a standalone application or as part of a broader platform — the following features are worth assessing:

  • HD audio codec support. Support for G.722 or Opus enables high-definition voice quality, which makes conversations clearer and reduces listening fatigue.
  • Presence and availability status. The ability to see whether colleagues are on a call, available, or away — and to set your own status — reduces unnecessary interruptions and improves team coordination.
  • Call transfer and conferencing. Attended transfer (speaking to the recipient before transferring), blind transfer, and multi-party conferencing are standard business telephony requirements.
  • CRM and application integration. Click-to-dial from a CRM record, automatic call logging, and screen-pop (displaying the caller's record when a call arrives) reduce manual data entry and improve agent efficiency.
  • Encryption. TLS for SIP signalling and SRTP for media. Both should be enabled by default, particularly for businesses handling sensitive customer information.
  • Call recording. Some softphones support local or cloud-based call recording. In regulated industries, confirm whether call recording is required and whether the platform supports compliant recording with appropriate retention and access controls.
  • Voicemail and visual voicemail. Access to voicemail from within the application, with the option to read transcribed messages rather than listening to recordings.

Use Cases: Who Uses Softphones

Softphones are used across a wide range of business contexts. The most common use cases are:

  • Remote and hybrid teams. Employees working from home or in a hybrid arrangement use softphones to maintain full access to their business phone number and team extensions without being tethered to an office desk. The experience is identical to being in the office — calls, transfers, and presence all work the same way.
  • Contact centers and customer support teams. Softphones integrated into contact center platforms allow agents to handle calls directly within the same interface they use for ticket management, scripting, and customer history. This reduces the number of screens and applications agents need to manage during a call. For more on how contact center operations use technology, see our overview of the MCC Contact Center platform.
  • Sales teams. Sales representatives using CRM-integrated softphones can click to dial directly from a contact record, have calls automatically logged with duration and outcome, and access call scripts or objection-handling notes within the same interface.
  • Distributed organisations. Businesses with multiple office locations can standardise on a single cloud phone platform and softphone application, eliminating the need to provision and maintain site-specific PBX hardware at each location.
  • Businesses reducing hardware costs. Replacing desk phones with softphones on existing employee computers eliminates per-device hardware cost, simplifies provisioning (a new employee's phone is set up via account creation rather than physical device configuration), and reduces the physical infrastructure at each site.

How to Get Started with a Softphone

Getting started with a softphone typically involves three steps: choosing a VoIP platform, provisioning user accounts, and installing the softphone application.

If your business already uses a cloud phone system or UCaaS platform, check whether a softphone application is included — most cloud communications platforms provide one as part of the service. If you are evaluating VoIP for the first time, our guide to VoIP for small business covers the key considerations before committing to a platform.

Once a platform is selected, users are provisioned with SIP credentials — a username, password, and SIP server address — which they enter into the softphone application. Many modern platforms simplify this further with QR code provisioning or single sign-on. After registration, the softphone is ready to make and receive calls on the user's business number.

For businesses with specific requirements around call volume, contact center functionality, or integrations, contact MCC to discuss how a cloud phone system with softphone support would work for your team.

Frequently Asked Questions

What is a softphone?

A softphone is a software application that enables voice calls over an internet connection using VoIP. It runs on a computer, smartphone, or tablet and replaces the need for a physical desk phone. Softphones typically provide the same features as a hardware phone — dialling, hold, transfer, conference, voicemail — along with additional capabilities like call history, contacts integration, and presence status.

What is the difference between a softphone and a VoIP phone?

A VoIP phone (also called an IP phone or desk phone) is physical hardware specifically designed to make calls over an IP network. A softphone is a software application that performs the same function on a general-purpose device such as a laptop or mobile phone. Both use SIP or a similar VoIP protocol. The main differences are hardware cost (softphones require no dedicated hardware), portability (softphones travel with the device), and the user experience (some users prefer the tactile experience of a physical handset).

Do I need special hardware to use a softphone?

No special hardware is required. Any computer, smartphone, or tablet with an internet connection and a microphone can run a softphone application. For better audio quality and comfort, many users pair a softphone with a USB or Bluetooth headset, particularly in contact center or high-call-volume environments. A headset is not mandatory — the device's built-in microphone and speakers work for occasional use.

Is a softphone secure?

Most enterprise-grade softphones encrypt signalling and media using protocols such as TLS (Transport Layer Security) for SIP signalling and SRTP (Secure Real-time Transport Protocol) for call audio. When evaluating a softphone or VoIP provider, confirm that both signalling and media encryption are enabled by default. On public or untrusted networks, using a VPN in addition to in-call encryption is a common security practice.

Can a softphone receive calls on a business number?

Yes. A softphone is registered to an extension or DID (direct inward dialling) number on your VoIP or UCaaS platform. When someone calls that number, the call rings on your softphone just as it would on a desk phone. If you are part of a team using a shared call queue or hunt group, you will receive calls distributed to that group based on the routing rules configured in your platform.

Cloud phone system with softphone included

MCC provides cloud communications infrastructure for businesses that want to replace desk phones with a flexible softphone experience. Contact us to discuss your requirements.

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