SJEs Still Stand: A Reaffirmation of Daniels v Walker and the Proper Use of Expert Evidence

In the world of family law financial remedies, expert evidence can make or break a case. But who gets to call the expert—and what happens when one party disagrees with the conclusions? The recent decision in BY v GC [2025] EWFC 226 (24 July 2025) provides a modern reaffirmation of the long-standing principles from Daniels v Walker [2000] 1 WLR 1382, supported by GA v EL [2023] EWFC 187.

Together, these cases make clear: Single Joint Experts (SJEs) remain the cornerstone of fairness, cost-efficiency, and procedural discipline in family litigation.

A Quick Recap: What Daniels v Walker Says

The 2000 Court of Appeal case remains the leading authority:

Parties may seek to rely on a second expert only if they have legitimate grounds for challenging the SJE’s opinion.
This must be done by application and in accordance with procedural rules—not via backdoor instructions or surprise evidence.
The court will balance the interests of justice, proportionality, and procedural fairness in deciding whether to permit departure from the SJE route.

BY v GC [2025] EWFC 226: A Sharp Reminder

In BY v GC, one party sought to introduce a second expert late in the day to counter a valuation provided by the SJE. The court took a firm line:

The application was refused as procedurally improper and unjustified.
There was no early indication that the SJE report would be disputed.
The second expert had not been jointly instructed and came without permission.

The judge reinforced the idea that where parties agree to a single expert, they are bound to that process unless a proper application is made, and even then, permission is granted sparingly.

GA v EL [2023]: More than Just Reinforcement

In GA v EL, Mostyn J addressed a similar issue—one party disagreed with the SJE report and tried to introduce a second opinion. He made clear:

There is no automatic entitlement to a second expert just because you disagree with the first.
Courts should discourage a “battle of experts” unless essential.
SJE procedure exists to reduce cost, delay, and forensic gamesmanship.

This case is a strong follow-up to Daniels, warning litigants that the court will enforce the procedural framework strictly.

Top 5 Tips for Practitioners

Treat SJEs as binding unless there is a genuine, well-founded concern.
Use Part 25 and Daniels v Walker procedure if challenging the SJE—don’t cut corners.
File applications early, ideally after seeing the draft report, with an initial view from a “shadow expert” if needed.
Don't delay: lateness alone can justify refusal.
Make sure clients understand that once a SJE is agreed, it’s not just another opinion—it’s the only one the court may hear without permission.

Final Thought

Between Daniels v Walker, GA v EL, and now BY v GC, the message from the courts is clear: expert evidence must be managed with discipline and care. SJEs aren’t just convenient—they are central to justice in financial remedy cases.

As the latest case shows, parties who sidestep the rules risk more than just a wasted report—they risk judicial disapproval, costs consequences, and an uphill battle in court.

If you're advising on an expert issue, make sure you’re playing by the Daniels rulebook.