By Jana Vidis, Group Marketing lead at Converged Solutions Group
The UK’s Public Switched Telephone Network (PSTN) switch-off is fast approaching, with the full shutdown scheduled for 31 January 2027.
The milestone marks the end of analogue telephony, the copper-based network that has supported communication in the UK for over one hundred years.
After this day, all services will move to digital IP-based technologies, such as VoIP, and there is no extension, no fallback, and no grace period for those who are not ready.
While this transition promises greater flexibility and efficiency, it also introduces a significant operational risk, particularly for legal and accountancy firms.
For legal firms specifically, the stakes are especially high because they rely heavily on trust, uninterrupted communications, secure records, and time-sensitive client interactions.
Solicitors and barristers depend on reliable, auditable communications to meet their professional obligations – from client care under the SRA Code of Conduct to court deadlines that cannot be missed. A failure in communications could constitute a breach of duty to clients or result in missed limitation periods carrying serious legal and reputational consequences.
Accountancy firms face equally pressing concerns: tax filing deadlines, audit signoffs, and real-time communication with HMRC are all time-critical activities where a communications outage can have direct financial and regulatory implications.
Yet, many legal and accountancy organisations are still underestimating the scale of the challenge.
Having guided numerous organisations through complex telecoms transitions, Jana Vidis, Group Marketing lead at Converged Solutions Group, understands exactly what is at stake, and what good preparation looks like.
Drawing on that experience, she has identified five critical steps that legal and accountancy firms need to take before it is too late.”
Step one: Audit your dependencies before the deadline does it for you
For many organisations, the biggest challenge is not the migration itself – it is visibility.
Before any migration can begin, businesses need a clear understanding of what they currently rely on.
This goes beyond desk phones and landlines. Analogue lines often sit behind critical systems that are easy to overlook, including alarm systems, lift emergency lines, door entry systems and payment terminals. Working with organisations across different sectors, these hidden dependencies are consistently the biggest source of delay and disruption when migration begins.
For legal and accountancy firms, the audit must extend to sector-specific systems. This includes dictation and audio recording equipment, document management systems with telephony integration, and any client portals or case management platforms that use legacy telephony connections.
Fax machines also deserve attention. Despite being widely considered outdated, fax remains in active use across many legal and accountancy practices – particularly for communicating with courts, HMRC, and overseas counterparts. These machines rely on analogue lines and will cease to function after the PSTN switch-off. Firms must plan now for secure digital alternatives, such as encrypted email or specialist online fax-to-email services, ensuring these meet the confidentiality requirements expected of regulated professionals.
When it comes to identifying services still running on the PSTN, a straightforward starting point is a review of billing statements – services still being paid for are often services still in use, even if nobody is actively monitoring them.
Furthermore, carrying out structured, thorough audits and mapping every analogue dependency across the business, not just the obvious ones, is the kind of rigorous groundwork that prevents costly surprises further down the line.
This is best handled by your in-house IT team or a trusted specialist partner. For organisations without in-house IT support, working with a trusted expert to carry out a full audit can be invaluable.
The risks of not completing a full audit should not be underestimated, because once the shutdown happens, there is no backup or extended support option.
Step two: Review connectivity and network readiness
Once dependencies have been identified, organisations must ensure their network can support digital alternatives.
Unlike analogue systems, digital voice solutions rely entirely on internet connectivity, which makes network performance critical.
Organisations should assess the type and quality of their broadband, their available bandwidth during peak hours, and whether their infrastructure can support multiple simultaneous calls alongside everyday business applications.
In Jana’s experience, this assessment frequently reveals that an upgrade to full fibre or a higher-capacity connection is essential.
Another aspect legal and accountancy firms must consider are the security implications of moving voice communications to IP-based infrastructure. Calls that previously travelled over dedicated copper circuits will now share internet infrastructure with other data. This introduces risks around call interception, eavesdropping, and data integrity that did not exist with analogue lines. Firms handling commercially sensitive transactions, litigation strategy, or confidential financial information should ensure that any new VoIP solution meets the encryption and data security standards required by their professional regulator – whether that is the SRA, ICAEW, ACCA, or another body.
Step three: Choose a solution built around how your business actually works
With the right connectivity in place, organisations can begin to assess the digital solutions available to them.
This stage is not a like-for-like replacement exercise. Organisations that simply replicate their analogue setup in a digital format miss the opportunity to work smarter. The goal is to adopt a solution that reflects how the business operates today and has the flexibility to scale as it evolves.
There is no single approach that fits every business. The right solution depends entirely on how your teams work, where they work, and how your business communicates with customers.
This is particularly relevant for legal and accountancy firms, where hybrid and remote working have become the norm since the pandemic. Fee earners, partners, and support staff may be working across multiple offices, from home, or in court, sometimes all on the same day. Digital telephony solutions offer the opportunity to unify communications across all of these locations under a single, coherent system, ensuring calls follow individuals, not desks.
Step four: Understand internal workflows and communication needs
To get the most from digital systems, organisations must understand how communication flows across their business and whether the current approach is still fit for purpose.
This means looking at call volumes, how calls are routed between teams, and how customer interactions are handled from the first point of contact.
For legal and accountancy firms, there are additional workflow considerations that are specific to the sector. Client confidentiality means that how calls are answered, recorded, and routed matters enormously.
Are client calls being answered in open-plan areas where conversations could be overheard? Are call recordings being stored securely and in line with data protection obligations? Are after-hours calls being handled in a way that maintains the professional standards clients expect?
The PSTN transition is an opportunity to address these questions proactively, designing communication workflows that are not only efficient, but also compliant and professional.
Step five: Migrate with a plan
The final stage is implementation, but this is more than a technical installation. For many organisations, it is the most complex and time-sensitive part of the entire process, and the one most likely to cause disruption if it is not managed carefully.
Businesses need to work closely with providers to understand timelines, potential disruption and the steps involved in migrating services. This includes planning for number porting, which can take up to ten working days, and ensuring contingency measures are in place if systems are temporarily unavailable.
For legal and accountancy firms, continuity of telephone numbers is a professional necessity. Client files, court documents, regulatory correspondence, and Companies House registrations may all reference your existing telephone numbers. Changing numbers without adequate notice risks clients being unable to reach you at critical moments, and may also create compliance complications if regulatory bodies hold incorrect contact details. Firms should ensure that number porting is planned well in advance, that clients are notified in good time, and that any transitional arrangements are clearly documented.
Just as importantly, organisations must prepare their people. Digital systems often change how employees work, so employees need to be trained so they are confident when the switch off takes place. Training should not be an afterthought, it must be seen as a core part of delivery.
Don’t wait for the dial tone to go silent
The PSTN switch-off represents a fundamental shift in how legal and accountancy organisations communicate and operate, and businesses cannot afford to wait until the deadline to act.
Instead, they must begin planning now, ensuring hidden dependencies are identified, connectivity is fit for purpose, and teams are ready to operate in their new modernised environments.
For regulated firms in the legal and accountancy sectors, the bar is higher than for many other businesses: the consequences of communications failure extends beyond inconvenience to potential regulatory, professional, and reputational harm.
The time to act is now.