Your PSTN Switch-Off Checklist: What Small Businesses Need to Do Before the 31st of January 2027

Your traditional phone line stops working on 31 January 2027. That’s a fact confirmed by BT, not a sales deadline. This checklist walks you through exactly what to check, what to do, and where TTNC can take the work off your hands.

What could be affected?

Run through this list. If any of it applies to your business, it’s time to plan your move.

• A PSTN or ISDN phone line, also known as the standard copper landline

• Broadband delivered over a traditional phone line

• Alarm systems, door entry or access control connected via the phone line

• Fax machines or card payment terminals on a phone line

Your business number doesn’t have to disappear with the old line. We can port it across to a hosted system before the cut-off, so your customers keep dialling the number they already know.

The six-step checklist

Step 1: Audit what you have

• List every phone number your business uses, including any lines tied to broadband or alarms

• Work out which are on PSTN or ISDN and which are already digital

• Note which numbers are business-critical and must be kept

Not sure what you’re working with? We offer a free service audit. We’ll go through your current setup and tell you exactly what needs to move, in plain English.

Step 2: Choose the right replacement

For most small businesses, the choice comes down to two options:

• TTNC VoIP User: fully hosted, works over your broadband, no expensive hardware to buy. Use a Yealink desk phone or the TTNC softphone app on your mobile.

• TTNC SIP Trunks: the better fit if you already have a PBX or handle higher call volumes.

Both are standard TTNC products: no contracts, no setup fees, no minimum term. You manage everything yourself through the myTTNC portal.

Step 3: Get your number ported

• We raise the port request with your current provider on your behalf

• Your number stays live throughout. The port typically completes within two weeks.

• Don’t cancel your old line until we confirm the port is complete

Step 4: Update your details

• Website, Google Business Profile and email signatures

• Social media profiles and third-party directories

• Any print, signage or vehicle livery carrying your number

Step 5: Test everything

• Make a test call in and out on your new TTNC system

• Check voicemail, call forwarding and any hunt groups are working. All configurable in real time through myTTNC

• Confirm any alarm or monitoring services have been updated to the new line

• Brief your team on any changes to how they answer or transfer calls

When should you start?

Now, before the January rush. Migration support gets stretched in the final weeks before the deadline. Businesses that act early move at their own pace, with full TTNC support behind them every step of the way.

Ready to get switch-off ready? We handle the whole process, including porting your number, with no setup fees and UK-based support throughout.

Your traditional phone line stops working on the 31st of January 2027. That's a fact confirmed by BT, not a sales deadline. This checklist walks you through exactly what to check, what to do, and where TTNC can take the work off your hands. 

What Could Be Affected? 

Run through this list. If any of it applies to your business, it's time to plan your move. 

• A PSTN or ISDN phone line, also known as the standard copper landline 
• Broadband delivered over a traditional phone line 
• Alarm systems, door entry or access control connected via the phone line  
• Fax machines or card payment terminals on a phone line 

Your business number doesn't have to disappear with the old line. We can port it across to a hosted system before the cut-off, so your customers keep dialling the number they already know. 

The Six-Step Checklist 

Step 1: Audit What You Have 

• List every phone number your business uses, including any lines tied to broadband or alarms 
• Work out which are on PSTN or ISDN and which are already digital 
• Note which numbers are business-critical and must be kept 

Not sure what you're working with? We offer a free service audit. We'll go through your current setup and tell you exactly what needs to move, in plain English. 

Step 2: Choose the Right Replacement 

For most small businesses, the choice comes down to two options: 

• TTNC VoIP User: fully hosted, works over your broadband, no expensive hardware to buy. Use a Yealink desk phone or the TTNC softphone app on your mobile. 
• TTNC SIP Trunks: the better fit if you already have a PBX or handle higher call volumes. 

Both are standard TTNC products. You manage everything yourself through the myTTNC portal. 

Step 3: Get Your Number Ported 

• We raise the port request with your current provider on your behalf 
• Your number stays live throughout. The port typically completes within two weeks. 
• Don't cancel your old line until we confirm the port is complete 

Step 4: Update Your Details 

• Website, Google Business Profile and email signatures 
• Social media profiles and third-party directories 
• Any print, signage or vehicle livery carrying your number 

Step 5: Test Everything 

• Make a test call in and out on your new TTNC system 
• Check voicemail, call forwarding and any hunt groups are working. All configurable in real time through myTTNC 
• Confirm any alarm or monitoring services have been updated to the new line  
• Brief your team on any changes to how they answer or transfer calls 

When Should You Start? 

Now, before the January rush. Migration support gets stretched in the final weeks before the deadline. Businesses that act early move at their own pace, with full TTNC support behind them every step of the way. 

Ready to get switch-off ready? We handle the whole process, including porting your number, with no setup fees and UK-based support throughout.