Quick answer
Your numbers come with you; the connectivity is what will catch you out. Since phones now run over the internet, the phone side of an office move is really a connectivity project with a porting exercise attached. The connection at the new site is the long pole - weeks for full fibre or SoGEA, considerably longer if new cabling is needed - so it should be ordered the day you sign the lease, not the month you move. Everything else, including the numbers, fits around that date.
The commercial point worth making early: the phone element of a move costs almost nothing if planned and a great deal if not. Emergency connectivity, parallel rental at two sites and a week of missed calls are all avoidable with a countdown. This guide is that countdown. If you want it run for you alongside the move, get a no-obligation quote.
Before you sign: survey the building
The single most valuable action on this page happens before the move is even confirmed.
Ask what connectivity is available at the exact address - not the street, the address. Full fibre coverage varies building by building, and a unit in an older estate or a multi-tenant block can be months behind the one next door. A site with no full fibre and no SoGEA availability is a materially different proposition from one with both, and it is worth knowing before rent is agreed rather than after.
In multi-tenant buildings there is a second question: who controls the risers and the incoming services? A landlord or managing agent may need to approve any new circuit, and that permission can add weeks. Ask early and in writing.
Our comparison of SoGEA and FTTP for business covers which you are likely to end up with and why it matters for calls.
The countdown
| When | What | Who |
|---|---|---|
| Before signing | Check connectivity availability at the exact address, and riser access | You, with your provider |
| 12 weeks out | Order the new connection. Do not wait for anything else | Your provider |
| 12 weeks out | Phone the alarm, lift and door-entry suppliers about both sites | You |
| 10 weeks out | Decide whether the move is also the moment to replace the phone system | You |
| 8 weeks out | Confirm handset, cabling and power requirements at the new site | You and your installer |
| 6 weeks out | Submit the number port, aligned to the move date | Gaining provider |
| 4 weeks out | Agree the fallback plan if the connection slips | You |
| 2 weeks out | Install and test the new connection ahead of anyone moving in | Provider |
| Move week | Cut over, test from outside, keep the old site live | You |
| 2 to 4 weeks after | Confirm everything works, then cease old lines and connection | You |
The two rows people compress are the first and the last. Ordering connectivity late is the classic failure. Ceasing the old site early is the expensive one - see the parallel-running section below.
Who arranges what
| Item | Who arranges it | Notes |
|---|---|---|
| New connectivity | Your telecoms provider | Order first, everything else follows |
| Riser and wayleave permissions | Landlord or managing agent | Can add weeks in multi-tenant buildings |
| Internal data cabling and power | You, or a cabling contractor | Handsets need data points, ideally powered |
| Number porting | Gaining provider | Align the date to the move, not before |
| Handsets and phone system config | Your provider | Handsets usually just travel with you |
| Alarm at both sites | Your alarm company | Old site decommission, new site install |
| Lift emergency line at the new site | The building's lift maintainer | Safety-critical and long lead time |
| Card terminals | Your card provider | Confirm they will work on the new connection |
| Ceasing the old services | You, afterwards | Never before the port completes |
The rows below the porting line are the ones no removals plan includes. A new building may have a lift with an emergency line, a door entry system and an alarm that all need arranging with whoever maintains them - and if the building is being switched off copper at the same time, those jobs are competing for the same scarce engineers. Start from devices that rely on phone lines.
Keeping your number when you move
| Move | Can you keep the number? | Notes |
|---|---|---|
| Within the same area code | Yes, straightforwardly | The standard case |
| To an adjacent area | Usually yes | Internet-based services are not tied to the exchange |
| A long way, keeping the old number | Usually yes | Common, and often desirable if the number is well known |
| A long way, wanting a local number instead | Yes, and keep both | Port the old one and add a new local number |
| Any move, with DDI ranges | Yes | Port the whole range, not the numbers in use |
A geographic number belongs to an area code, not an address, and an internet-based service can deliver it anywhere. So a business moving from Manchester to Burnley can keep its 0161 number, add an 01282 number, and publish whichever suits each audience. That flexibility did not exist on copper.
The mechanics, timings and the reasons ports get rejected are covered in keeping your business landline number. The one rule bears repeating here because moves are exactly when it gets broken: never cease the old line before the number has ported.
Budget for parallel running
This is the line item that gets left out of move budgets, and it is the one I would insist on.
For a period around the move you will be paying for connectivity and lines at both sites. Two to four weeks is typical and sensible. It buys you three things: the ability to install and test the new connection before anyone depends on it, a working fallback if the move slips, and protection for your numbers during the port.
Set against that, the cost of getting it wrong is a business with no phones on its first week in a new building - at precisely the moment customers are most likely to be checking whether you have survived the move. Budget the overlap explicitly so nobody tries to save it later.
The fallback plan
Assume the new connection might not be live. It is not a reflection on anyone; installs slip.
The plan is simple and should be arranged weeks in advance rather than improvised on the day. Configure your main number to divert automatically to a mobile or a group of mobiles, and know how to switch it on. If your service supports it, set the divert as a rule that triggers when the office has no registered handsets, so it happens without anybody remembering.
A 4G or 5G failover at the new site is the more complete version, and worth it if the business genuinely cannot trade without phones. Either way, test the fallback before you need it.
Make the move an upgrade
You are changing everything anyway, so an office move is the natural moment to stop paying for the past:
- Drop legacy line rental you have been carrying for years.
- Re-size capacity to your actual peak rather than reproducing the old setup.
- Retire anything nobody has used since the last move - the fax line is the usual candidate.
- Fix the numbering plan: who needs a direct number, what the main number should do out of hours.
- If your lines are still analogue or ISDN, do the migration and the move as one project rather than two. Our switch-off checklist folds neatly into a move plan.
The bottom line
The phones are not the hard part of an office move; the connection is. Check availability before you sign, order the day you do, port the numbers to align with the move date, budget honestly for a few weeks of running both sites, and have a divert-to-mobile fallback configured before you need it. Do those five things and the phones become the least dramatic part of the whole exercise - which is exactly what you want on week one in a new building.
Moving soon? Tell us the new address and we will check what it can actually get, then plan the phones around your move date: get a no-obligation quote or call 0333 006 9399.
Getting unknown calls on a business line? Our free UK phone number checker shows which network or provider Ofcom allocated any number to, and whether the range is in service — no sign-up.
Frequently asked questions
Can I keep my phone number when I move office?
Yes, in almost every case. A geographic number belongs to an area code rather than a precise address, and an internet-based service can deliver it anywhere - so you can keep an 0161 number after moving out of Manchester. DDI ranges move too, provided you port the whole range rather than the numbers in use.
How early should I plan the phone side of an office move?
Order connectivity at the new site the day the lease is signed. Full fibre and SoGEA installs run to weeks, and longer where new cabling or landlord permission is needed. Everything else - porting, handsets, configuration - fits around that install date rather than the other way round.
What is the hardest part of moving phones to a new office?
Connectivity lead times, by a wide margin. The phone service itself can be configured in a day, but it cannot exist without a working connection at the new address. Check availability before you commit to a building, and order the moment you do.
Do I need new phone lines at the new office?
No - you need a suitable internet connection. There are no phone lines to order any more. Your handsets can usually travel with you and plug into the new network, provided there are data points and power where the phones need to be.
Should I keep the old office lines running during the move?
Yes, for two to four weeks. Parallel running lets you install and test the new connection before anyone depends on it, gives you a fallback if the move slips, and protects your numbers while they port. Budget for it explicitly, because it is the item most often cut from a move plan.
What happens if the new connection is not ready on move day?
Nothing, if you planned for it. Configure an automatic divert of your main number to mobiles, arranged weeks in advance and tested. Keeping the old site live for a few weeks gives you a second safety net. A 4G or 5G failover at the new site is the more complete answer.
What about the alarm, lift and door entry at the new building?
Each needs arranging with the company that maintains it, and none of it is part of a telecoms order. If the new building is also moving off copper, those engineers are in demand, so make the calls twelve weeks out rather than in move week.