Cybersecurity for Law Firms: A Practical Guide

Law firms sit on two things every cybercriminal wants: large sums of client money moving through client accounts, and highly sensitive, often privileged information about deals, disputes and personal affairs. That combination makes the legal sector a consistently attractive target, and the National Cyber Security Centre (NCSC), the UK government's authority on cyber threats, has said as much directly. This guide sets out why firms are targeted, the attack methods that keep working against them, what the Solicitors Regulation Authority (SRA) expects firms to do about it, and the practical controls that make the biggest difference — for everyone in the firm, not just IT.

Why law firms are a high-value target

In its Cyber Threat Report for the UK legal sector, the NCSC put the scale of the industry in context: legal services contribute around £44 billion to the UK economy and employ more than 320,000 people across roughly 33,000 businesses (NCSC, 2023). That size and the volume of money moving through client accounts — conveyancing completions, probate distributions, settlement payments — make firms of every size a worthwhile target, not just the largest names on the high street.

Sensitive information adds a second motive. Correspondence about a merger, a family dispute, a criminal matter or a client's finances can be valuable in its own right — for extortion, for insider advantage, or simply to sell on. Smaller firms are not exempt: the NCSC specifically flagged that many smaller practices rely on external IT suppliers, which can widen the attack surface if that supplier itself is compromised.

Investment in defences has not always matched the risk. The NCSC's 2023 report noted that the UK's top 100 firms spent an average of only 0.46% of fee income on cybersecurity in 2022 — a figure worth bearing in mind before assuming "someone else" is dealing with this.

The attack methods that keep working

Business email compromise and payment diversion fraud

The single most damaging attack against law firms is business email compromise (BEC) — where a criminal gains access to, or convincingly spoofs, an email account to redirect a payment. In legal practice this most often shows up as payment diversion fraud on conveyancing and probate matters: a fraudster monitors or intercepts email correspondence about an upcoming transfer, then sends the client (or the firm) revised bank details at exactly the moment funds are due to move. Because the request looks like it comes from a trusted party mid-transaction, it is often acted on without a second thought — with life-changing consequences for the client and severe regulatory and reputational consequences for the firm. Our companion guide on payment diversion fraud and client account risk goes into the mechanics of these scams and how firms typically discover they have been hit.

Phishing impersonating clients, courts and suppliers

Phishing remains the entry point for most serious incidents. Emails impersonating clients, opposing solicitors, HM Courts & Tribunals Service or even the SRA itself are used to harvest login credentials or persuade staff to open a malicious attachment. Once inside a mailbox, criminals often sit quietly, reading correspondence and waiting for a live transaction before acting — which is why a compromise can go unnoticed for weeks.

Ransomware and data extortion

Ransomware attacks encrypt a firm's systems and demand payment for their release, frequently combined with a threat to publish stolen client files if the ransom is not paid. For a law firm this is not just an IT outage: it can mean an inability to meet court deadlines, breach of client confidentiality, and weeks of disruption while systems are rebuilt.

What the SRA expects from firms

The SRA treats cybersecurity as a mainstream part of a firm's regulatory obligations, not a niche technical issue. Its guidance is blunt about the stakes: successful attacks have seen clients lose the proceeds of a house sale, and firms forced to close after being tricked into paying money to fraudsters. The SRA has also taken enforcement action where firms or individuals missed clear warning signs — in one case in 2024, a solicitor was fined £26,000 for failing to spot the red flags of a cyber-enabled scam.

Firms are expected to have proportionate systems and controls in place to identify and manage cyber risk as part of their wider risk management under the SRA Standards and Rules, with client money protection sitting alongside those obligations. That links directly to a firm's accounts rules compliance — see our explainer on SRA Accounts Rules and client money controls for how cyber risk and client account safeguards fit together. The SRA also publishes regular scam alerts — 278 were issued between January 2022 and January 2023 alone — and firms are expected to act on the patterns those alerts describe, not treat each one as an isolated warning.

Practical controls that make the biggest difference

None of the controls below require a large budget to start. What they require is consistency, and buy-in from every level of the firm, from reception to the managing partner.

• Verify bank detail changes by phone, on a number you already hold. Never call a number given in the email that requested the change. Ring the client or firm using a number taken from an earlier, trusted communication or the file, and confirm the change verbally before any transfer proceeds.
• Use Confirmation of Payee. Where the receiving bank supports it, check that the account name matches the payee before sending funds — a simple additional check that catches many diversion attempts.
• Turn on multi-factor authentication (MFA) for email, case management systems and remote access. MFA — requiring a second proof of identity beyond a password, such as a one-time code — is one of the single most effective defences against account takeover.
• Train every member of staff, regularly. The SRA specifically encourages a "no blame" culture, so staff report suspicious emails or mistakes quickly rather than hiding them. Training should cover how to spot look-alike domains and subtle impersonation (a lower-case "l" swapped for a "1", for example), not just generic advice.
• Keep software and devices patched, run reputable antivirus and firewall protection, and encrypt and enable remote wipe on mobile devices that hold client data.
• Back up data regularly and test the restore process, so a ransomware attack does not become an existential threat.
• Consider recognised certification such as Cyber Essentials, ISO 27001 or Lexcel, which give a structured baseline and can support both insurance and client due diligence requirements.

Incident response basics

Every firm, regardless of size, should have a short, clear incident response plan that everyone can follow under pressure. At a minimum it should identify who to alert immediately (a named cybersecurity lead or equivalent), how to isolate affected systems, when and how to notify the Information Commissioner's Office and, where client money or SRA-regulated activity is affected, when to notify the SRA. It should also cover client communication — clients need to hear about a serious incident from the firm, promptly and honestly, not find out some other way. Firms that have never rehearsed this plan tend to lose valuable time in the first, most critical hours of a real incident, and partners and managers should be alert to warning signs well before a full-blown crisis develops.

FAQs

Is cybersecurity training mandatory for law firm staff?

The SRA does not prescribe a specific training course, but it does expect firms to have effective systems and controls to manage cyber risk, and staff training is central to meeting that expectation. Given how often BEC and phishing scams succeed because a member of staff acted on a convincing but fraudulent email, regular training is, in practice, essential to demonstrating compliance.

What should I do if I suspect a client's bank details have been changed by a fraudster?

Stop any pending transfer immediately, do not use any phone number or contact detail in the suspicious message, and call the client or the other side using a number you already hold on file. Report the incident internally under your firm's no-blame policy so it can be investigated and, where money has already been sent, contact your bank straight away — speed significantly affects the chance of recovery.

Does cyber insurance replace the need for these controls?

No. Cyber insurance can help with recovery costs, but insurers increasingly expect evidence of basic controls such as MFA and staff training before paying out, and no policy will restore a client's trust or reverse the reputational damage of a serious breach.

Final thought

Cybersecurity for law firms is not primarily a technology problem — it is a people and process problem with technology support. The firms that fare best treat it as part of everyday practice management: verify before you pay, train continuously, and know exactly what to do in the first hour of an incident. For CPD that builds this and related risk management knowledge into your annual development plan, explore Learnsignal's CPD courses.