VoIP business phone services make phone calls over internet. The biggest disadvantage is that if you do not have a reliable internet connection, then your customer call quality will not be as good.
Also if your business experiences a power outage, then it likely means that your internet router will also lose power. This can lead to call dropping. We always recommend using a battery backup with your internet router to avoid call quality issues.
These disadvantages can be easily mitigated, and the advantages of VoIP business phone systems simply outweigh any cons.
You get all the advanced call features like call routing, music on hold, conference calls, auto-attendant, interactive voice response (IVR), call queuing, extension dialing, voicemail forwarding, video calling, and a lot of flexibility without the high the high costs of landline phones.