- Web Development
How to Set Up Email Capture and Lead Magnets
30 Dec, 2025
Future-proof your retail communications with a seamless ISDN-to-SIP migration.
Openreach is switching off ISDN across the UK. We ensure your business is migrated well ahead of the deadline with zero disruption.
Modern VoIP alternatives offer features ISDN never could — video calling, mobile integration, and flexible call routing.
Most businesses see significant monthly savings after migrating from ISDN to VoIP, often reducing telephony costs by 40% or more.
Cloudswitched provides modern ISDN replacement solutions for UK retail, migrates your business from legacy ISDN lines to modern SIP trunks and VoIP, ahead of the 2025 PSTN switch-off, with improved call quality and lower costs. We audit your existing ISDN usage, design a modern SIP-based replacement, and manage the entire migration so your store managers and retail staff experience no disruption to their communications.
A clear, structured process from consultation to ongoing support.
We audit every ISDN line, channel, and number in your business — including those used for alarms, lifts, fax machines, and card payment terminals — to ensure nothing is missed.
Based on your audit, we recommend the right combination of VoIP, SoGEA, and analogue adapters to replace every ISDN service with a modern equivalent.
We port your numbers, configure new systems, and test everything before decommissioning your old ISDN lines. Your team experiences zero downtime during the switch.
We port your existing telephone numbers and replicate your current call routing, so your store managers and retail staff and clients experience zero disruption when ISDN lines are replaced with SIP trunks.
SIP trunks typically cost 40-60% less than equivalent ISDN lines. For retail with multiple lines across stores, warehouses, and head offices, the savings are substantial and immediate.
Modern SIP trunks deliver HD voice quality that surpasses ISDN, ensuring your store managers and retail staff present professionally on every call with clients, suppliers, and retail contacts.
Unlike ISDN, SIP trunks integrate with modern retail platforms and support features like video calling, call recording, and CRM integration with Shopify POS, Vend, and inventory management platforms.
Hundreds of successful ISDN migrations for retail across the UK
Understanding of retail telephony requirements and call patterns
Number porting with zero downtime and no lost calls during migration
Integration expertise with Shopify POS, Vend, and inventory management platforms for click-to-call and call logging
Free ISDN audit identifying all lines, usage patterns, and migration priorities
UK-based support team available throughout the migration and beyond

The UK PSTN switch-off means all ISDN lines will stop working. Openreach has already stopped selling new ISDN lines and is actively migrating exchanges. Retail should begin their migration now to avoid service disruption and secure the best SIP pricing.
No. Cloudswitched ports all your existing telephone numbers to SIP trunks, so your store managers and retail staff, clients, and all published contact details remain unchanged throughout the migration.
Most retail save 40-60% on line rental and call charges by migrating from ISDN to SIP trunks. A typical stores with 8 ISDN channels saves approximately £200 per month, adding up to over £2,400 annually.
We audit all ISDN-dependent equipment including alarm panels, fax machines, and EPOS terminals. Each device is migrated to a suitable IP-based alternative, ensuring no retail system loses functionality during the transition.
A typical ISDN migration for retail takes 2 to 6 weeks from audit to completion. Cloudswitched manages the entire process, including number porting, SIP configuration, and handset setup, with a dedicated project manager for your retail migration.
Limited time offer - valid until 31/05/2026
Get ahead of the switch-off. Share your details and we will conduct a free audit of your ISDN estate.
Submit your details and one of our friendly team members will be in touch shortly
Powered by industry-leading technologies including SolarWinds, Cloudflare, BitDefender, AWS, Microsoft Azure, and Cisco Meraki to deliver secure, scalable, and reliable IT solutions.