Portability
Business VoIP services provide seamless access to an organization's phone system from anywhere, to all of its employees. Sometimes users are at home, working in remote locations. VoIP allows such workers to use any device they have with the same number as their work, thus protecting their privacy and offering a professional image to all callers.
As VoIP is not tied to a particular location or prefix, not only does it eliminate long distance charges for calls within the same office, but also the phone can be used from the location where the employee is working that day.

Lower maintenance cost
Business using cloud VoIP services do not have to worry about maintenance, repairs or upgrades. This means they don't have to hire consultants or full-time employees just to manage the phone system.
Even organizations that use local solutions with SIP trunks can be freed from the hassle associated with maintaining two different networks, as VoIP allows them to route phone calls through the same network that they use to send files or emails.

Reduce expenses
All companies seek to reduce costs in an effort to remain profitable. VoIP enables businesses to do just that:
The elimination of charges for calls between employees of the same company, even if they are in different offices.
Lower cost per call, both for local and long distance calls.
Provide unlimited calls for a fixed monthly price according to the chosen rate.

Integrate with other business applications
Companies have realized that keeping information in airtight compartments is wasting its potential. This is why software and applications that freely share data have become more valuable than those that keep it locked away.
The same is true for the company phone system. Many VoIP providers are offering integration with business applications such as CRM to make it easier for employees to use and exchange data.

Improve productivity and response time
VoIP offers many advanced features such as visual voicemail, digital fax, and group inboxes that enhance productivity. For example, faxes can be sent in the same way that email is written, eliminating the need for the user to go to the fax machine to send or receive a fax.
These features also eliminate the delay in responding to customer calls, support requests, or other questions. Sales department customer voicemails can be sent to a group inbox to be answered by any employee who is available at the time.

The biggest drawbacks of VoIP is that organizations need a high-speed Internet connection at all times. If the Internet is disconnected for any reason, the phone system will stop working.

Most organizations have backups in case this occurs, but for now at least, companies operating in locations without reliable Internet access should not implement VoIP.

Another drawback is that power is required for IP phones to work, making them less useful in the event of disasters. Organizations often connect their phones to standby power supply and can be used until their battery runs out.

As you can see, these are not insurmountable obstacles and many organizations manage to overcome them. In general, business VoIP has many advantages for any organization.