Running Both Locations: The Overlap Period

Moving Your Office Without Losing Your Mind (or Your Phones): Part 4 of 8

For some period of time during your move, you'll be paying for two of everything. Two internet connections, two sets of phone service (or at least the ability to receive calls at both locations), two sets of utilities. It's tempting to minimize this overlap to save money, but the overlap period is actually one of the most valuable phases of the entire move. It's your safety net, your testing window, and your insurance against the unexpected.

The businesses that have the smoothest moves are the ones that budget for a generous overlap and use it well. The businesses that have the worst moves are the ones that try to switch everything on a single weekend and discover problems on Monday morning when customers are calling and employees need to work.

How long should the overlap be

The right overlap depends on the complexity of your setup and your tolerance for risk. Here are some general guidelines.

Minimum: two weeks. This gives you time to install and test the internet connection at the new location, set up and test a few phones, and verify that the basic infrastructure works before committing to the move. Two weeks is tight and assumes everything goes smoothly.

Recommended: four weeks. This provides enough time to thoroughly test the new location's connectivity under real conditions, including different times of day and different usage patterns. It also provides buffer for the unexpected: an installation delay, a configuration issue that takes a few days to resolve, or a number porting timeline that slips.

For complex setups: six to eight weeks. If you're running an on premises PBX, have a large number of extensions, operate a call center, or have specialized equipment (conference room systems, analog fax machines, door buzzers connected to the phone system), give yourself more time. Each additional component increases the chance that something needs adjustment, and having the old location as a fallback gives you the space to troubleshoot without affecting business operations.

What to do during the overlap

The overlap period isn't dead time. It's an active testing and validation phase. Here's what should happen.

Week 1: Infrastructure validation

The internet connection should already be installed at the new location (if you followed the timeline from the first post in this series). During the first week of overlap, connect a computer and a phone to the new connection and test thoroughly.

Run speed tests at different times of day. Morning, midday, and afternoon results can vary significantly on shared connections, as covered in the Getting the Internet Right series. Run a VoIP quality test to measure latency, jitter, and packet loss under realistic conditions. Place test calls from the new location and listen carefully for audio quality. If you have a second person available, have them call you at the new location from an external number and evaluate the quality from both sides.

If the numbers look good and calls sound clean, you're off to a solid start. If there are issues, you have time to address them: adjusting QoS settings on the router, contacting the ISP about connection quality, or adding a backup connection if the primary isn't performing as expected.

Week 2: Equipment setup and configuration

Move a subset of equipment to the new location and configure it. Set up the router or firewall with your production configuration (not a temporary test config). Connect several phones and verify registration, inbound calls, outbound calls, transfers, hold, voicemail, and any other features your team uses daily.

If you're running an on premises PBX, this is when you'd set up the PBX at the new location. Some businesses run the PBX at the new location with a VPN or WAN link back to the old location during the transition, allowing phones at both locations to work off the same system. Others set up a new PBX instance at the new location and migrate extensions individually. The approach depends on your specific setup.

For cloud hosted phone systems, the PBX is in the provider's cloud and doesn't move. You just need phones at the new location that can register to the same provider. This is significantly simpler than moving an on premises system.

Week 3: Partial move and real world testing

Move a small group of people to the new location and have them work there for a few days using the new infrastructure. This is the real world test that catches issues that controlled testing misses. Maybe the WiFi has a dead spot in the corner conference room. Maybe the firewall is blocking a specific cloud application. Maybe the QoS configuration works for five people but needs adjustment for the full team.

Having a small group at the new location while the rest of the team remains at the old location also tests the ability of the two locations to communicate. Can people at the new office call extensions at the old office? Can they participate in the same conference calls? Can they access the same shared resources?

Week 4: Full move

With the infrastructure validated, equipment configured, and a partial move successfully completed, the full move is much lower risk. The remaining team moves to the new location. Phones are plugged in, and because the infrastructure is already proven, people should be able to start working almost immediately.

This is also typically when the number port completes (if you're changing providers). The permanent numbers switch over to the new provider, calls start arriving at the new location, and the transition is complete.

Cloud PBX versus on premises PBX during a move

The type of phone system you have significantly affects the complexity of the move.

Cloud/hosted PBX: The phone system itself doesn't move. Your phones register to the provider's servers over the internet. At the new location, you plug in phones, they connect to the internet, register with the cloud provider, and they work. Your extensions, voicemail, auto attendant, ring groups, and all other configuration stays the same because it's all on the provider's servers. This is the easiest scenario.

The main consideration is that the new internet connection needs to be good enough for VoIP. If you're going from a dedicated fiber connection at the old office to a cable connection at the new office, call quality might change even though the phone system is identical. Test call quality at the new location before the full move.

On premises PBX: The phone system is a physical server (or virtual machine running on a physical server) that lives in your office. Moving it means either physically relocating the server to the new location, or setting up a new instance and migrating the configuration.

Physical relocation means the PBX is offline during transit, which means your phones don't work during that period. This needs to happen during off hours, and you need to have tested the new location's internet connection with the PBX before committing to the move. The PBX connects to the SIP trunk through the internet, and if the new connection has a different public IP address (which it almost certainly will), the trunk configuration needs to be updated. If your trunk uses IP authentication, you need to inform your trunk provider of the new IP address before or during the cutover.

Migration to a new instance is cleaner but more work. You set up a new PBX at the new location, configure it with the same settings, and test it alongside the old one. When you're ready to cut over, you point the SIP trunk to the new PBX and switch phones to register with the new system. The old PBX stays running at the old location as a fallback until you're confident the new one is stable.

Maintaining phone service during the gap

Even with careful planning, there may be a brief period during the physical move when phones at the old location are disconnected and phones at the new location aren't yet fully operational. Minimize this gap, but also plan for it.

Call forwarding. Before disconnecting phones at the old location, activate call forwarding on your main numbers to mobile phones or an answering service. This ensures that calls from customers are still answered even if the office phones are temporarily down.

Voicemail. Make sure your voicemail system continues to work during the transition. If voicemail is part of your cloud PBX, it'll keep working regardless of which location the phones are at. If it's on your on premises PBX and the PBX is being moved, voicemail will be unavailable during transit. Set up a temporary greeting letting callers know about the move and when normal service will resume.

Mobile phones. Your team's mobile phones work regardless of the office move. For the brief period when office phones might be unavailable, having key staff reachable on their mobiles provides continuity.

Disconnecting the old location

Once the move is complete, the number port is done, everything at the new location is working, and you've had at least a few days of normal operations to confirm stability, you can disconnect the old location.

Cancel the internet service. Check your contract terms for any early termination fees if you're still within a term commitment. If possible, time the cancellation to coincide with the end of a billing cycle to avoid paying for a partial month.

Return equipment. If you're renting a modem or router from the ISP, return it to avoid equipment charges.

Cancel phone service at the old location. If you had phone service separate from your VoIP system (an analog line for a fax machine or alarm system, for example), cancel those lines.

Document everything. Keep records of cancellation dates, confirmation numbers, and final bills. Disputes about service charges after a move are not uncommon, and documentation protects you.

Next up: Move Day: What to Bring Up First and What to Test, the practical sequence for getting operational at the new location.