One-Time VoIP Costs: What You Pay Once and Never Again

When you switch to VoIP, you’re not just paying monthly fees—you’re also facing one-time VoIP costs, upfront expenses you pay only when setting up your system, not every month. These include things like buying IP phones, porting your old number, or paying for initial configuration. Unlike recurring charges for minutes or bandwidth, these are one-off payments that happen at the start—and if you don’t plan for them, they can sneak up on you.

One of the biggest one-time VoIP costs, upfront expenses you pay only when setting up your system, not every month is VoIP hardware, physical devices like IP phones, gateways, or SIP adapters needed to connect your analog phones or legacy systems to a digital network. You might think your existing phones will work, but most landline handsets won’t connect to a VoIP system without an analog gateway, a device that converts signals between traditional phone lines and digital VoIP networks using FXS or FXO ports. That’s a $50–$200 expense right there. Then there’s SIP trunking setup, the process of connecting your VoIP system directly to the public phone network via an internet connection, often requiring configuration fees or one-time activation. Some providers charge $100–$300 just to activate your SIP trunk, even if your monthly usage is free.

Don’t forget virtual phone numbers, local or toll-free numbers hosted in the cloud that don’t require physical lines, often charged as a one-time setup fee when first assigned. Porting your existing vanity or toll-free number? That’s another one-time hit—sometimes $25, sometimes $150—depending on your carrier and country. And if you’re moving from an old PBX system, you might need a transcoding engine, a system that converts between different audio codecs to ensure compatibility across devices or custom integration with your CRM, both of which can add a few hundred dollars to your startup costs. These aren’t monthly bills. They’re setup fees. Pay them once, and they’re done.

What’s surprising is how many businesses overlook these costs because they’re focused on monthly savings. You save on long-distance calls, yes—but if you didn’t budget for the upfront stuff, you might end up spending more than you expected. The good news? Once you pay these, they’re behind you. No renewals. No subscriptions. Just your new system running smoothly.

Below, you’ll find real-world breakdowns of what these one-time costs actually look like—from porting a toll-free number to hardening your SIP setup against fraud. No fluff. Just what you need to know before you click "Buy" or "Activate."