Given the advantages of VoIP over ISDN, and the issues with ordering legacy services, we recommend not. Whether or not the 2025 date will stick remains to be seen. The final date is dependent on how successful UK wide fibre rollouts are, as without the connectivity to run there is no real alternative to ISDN. Connectivity in the UK is getting faster and more stable, so who knows it may happen even sooner than 2025. But while the date may move by a few years here or there, the one certainty is this; ISDN and PSTN are outdated technologies that are simply not as good as modern VoIP. So don’t stay in the past.