JXX v Archibald [2026] EWHC 2404 (SCCO): Who Pays the Costs of the MRO Dispute?

A receiving party can suffer a substantial reduction on detailed assessment and still be the successful party for costs.

That is one of the clearest lessons from JXX v Scott Archibald [2026] EWHC 2404 (SCCO), handed down by Senior Costs Judge Rowley on 18 September 2026. It is the latest stage of the litigation concerning Medical Reporting Organisation (“MRO”) fees in JXX v Archibald and HLA v LXA & EUI Ltd.

The substantive MRO decision in March 2026 attracted considerable attention because the court rejected the so-called Stringer Cap, treated MRO charges as disbursements rather than outsourced solicitors’ profit costs, rejected the suggestion that deferred payment and write-off arrangements were automatically irrecoverable funding costs, and concluded that no more than a 25% mark-up on the underlying expert fees was reasonably recoverable between the parties. We examine that decision in detail in our note on whether the recoverable MRO mark-up is now capped at 25%.

The latest judgment does not revisit that 25% conclusion. Instead it answers the next question: after all of that litigation, who actually won — and who should pay the hundreds of thousands of pounds spent arguing about it?

The answer was predominantly the claimants and the MROs. But not completely. And that distinction makes the judgment considerably more useful than a simple “costs follow the event” decision.

The short answer

Senior Costs Judge Rowley held that the claimants and MROs were the successful parties on the general MRO issues. They were awarded those costs without any percentage reduction, despite the fact that the MRO fees in HLA had themselves been reduced by approximately 40%. However:

• the Defendant in JXX was awarded the costs of the earlier disclosure application;
• the claimants and MROs received the costs of the joinder applications;
• the confidential disclosure application’s costs were made costs in the case;
• the general costs are to be assessed on the standard basis by detailed assessment if not agreed;
• and the court declined to order a payment on account while the substantive MRO decision is under appeal.

For costs practitioners, perhaps the most useful point is this: a substantial reduction in the amount claimed does not necessarily convert the receiving party into the unsuccessful party. Success depends upon what the dispute was actually about and what the parties achieved.

What was this judgment about?

The substantive MRO issues had already been decided. The hearing leading to the new judgment was concerned with the costs consequences of that litigation. Senior Costs Judge Rowley identified four main categories of disputed costs:

• the earlier decision requiring JXX to elect whether to provide information about the MRO charges;
• the applications joining the MROs to the proceedings;
• a confidential disclosure application; and
• the general costs of litigating the MRO issues, particularly preparation for and attendance at the four-day hearing in November 2025.

These were not modest costs. By the time the parties reached the consequential hearing, the claimant-side costs were well into the hundreds of thousands of pounds. That itself ultimately affected the method by which those costs would be assessed.

The starting point: CPR 47.20

CPR 47.20 normally gives the receiving party the costs of detailed assessment proceedings unless another rule or enactment provides otherwise, or the court makes some other order. When considering whether some other order should be made, the court must have regard to all the circumstances, including the parties’ conduct, the amount by which the bill has been reduced, and whether it was reasonable to claim or dispute a particular item.

Senior Costs Judge Rowley described the normal rationale in characteristically direct terms: if the paying party wants the successful party’s costs examined in detail, the usual starting point is that the paying party bears the costs of doing so.

But these MRO proceedings were unusual. The litigation had developed into something much closer to a standalone application or test dispute than an ordinary line-by-line detailed assessment. The judge therefore preferred to analyse success principally through CPR 44.2 and the ordinary question: who was the successful party?

Both sides said they had won

Perhaps unsurprisingly, everybody said they had succeeded. That was complicated further by the fact that all sides had appealed the substantive decision. But the judge still had to identify the practical winner of the first-instance litigation, and to do that he looked at the issues actually decided.

The Defendants lost the Stringer Cap argument

One of the central Defendant arguments was based upon Stringer v Copley. The Defendants contended that recoverable MRO charges should effectively be restricted by reference to the work a solicitor would otherwise have undertaken, supported by a corresponding breakdown. Senior Costs Judge Rowley rejected that approach in the March judgment.

In the September costs decision he described the Stringer Cap as a central argument of the Defendants and accepted the thrust of the claimant-side submission that the practical Defendant position was that little or nothing should be payable to the MRO one way or another. That was an important part of deciding who had won: the claimants and MROs had succeeded in establishing that MRO charges were capable of substantive inter partes recovery without having to recreate a fictional solicitor’s time ledger.

But the claimants did not win everything

There was an equally important claimant argument which failed. The claimants had argued that the medical evidence charge could simply be treated as a unitary disbursement, without separating or explaining the constituent MRO element. Senior Costs Judge Rowley rejected that position. The court had required information enabling the MRO element to be separated from the experts’ own charges. That became particularly important when the court dealt with the costs of the earlier disclosure application.

So the result was not that the claimants won everything. It was much more nuanced:

• the Defendants lost their central Stringer approach;
• the claimants lost the argument that the whole medical evidence invoice could remain an unexplained unitary disbursement;
• and the court nevertheless found for the claimants and MROs on most of the substantive issues.

Why the claimants were still the successful parties

At paragraph 21, Senior Costs Judge Rowley concluded that the claimants and MROs had been successful on most of the issues raised. Their successes included defeating the Stringer Cap argument, succeeding on the treatment of administrative-type MRO fees, and succeeding on the funding-cost arguments. The main issue on which they had not succeeded was the level of the recoverable mark-up, described in the submissions as the 25% cap issue.

The judge then looked at the practical result. The claimants emerged with an order requiring the Defendants to pay sums which would not have been payable had the Defendants’ position prevailed. In the judge’s words, they had required the Defendants to “write a cheque”. They were therefore the successful parties for CPR 44.2 purposes.

That is the first major lesson from the case: success is assessed by looking at the litigation as a whole, not merely by calculating what percentage of the original monetary claim survived.

The 40% reduction did not make the claimants unsuccessful

This is probably the most commercially useful part of the new judgment. In HLA, the claimant side pointed out that if the entire medical disbursement were compared with what was ultimately allowed, the reduction was only around 12%. That figure was influenced by the fact that the underlying experts’ professional fees had not been challenged. Looking specifically at the MRO element, however, the reduction was approximately 40%.

Senior Costs Judge Rowley accepted that a 40% reduction would ordinarily be a significant factor when deciding the costs of an assessment. CPR 47.20 expressly requires the court to consider the amount by which a bill has been reduced. But that did not end the analysis. The judge accepted that even a substantial reduction would not ordinarily transform the successful party into the unsuccessful party. At most, it might justify reducing the percentage of the successful party’s costs recoverable. On these facts, the court did not even make that percentage reduction: the claimants and MROs received the general costs of the MRO litigation without any percentage reduction.

A reduction and success are different questions

Suppose a receiving party claims £100,000 and the court allows £65,000. That does not automatically mean the receiving party “lost” 35% of the assessment. The court may need to consider what the assessment was actually about: whether the paying party’s fundamental arguments were rejected, whether the receiving party established an entitlement the paying party said did not exist, whether the reduction was simply a matter of quantum, whether offers were made, and whether it was reasonable to claim or dispute the relevant items. Those questions can affect the eventual costs order considerably.

This does not mean the size of the reduction is irrelevant

The opposite conclusion would also be wrong. JXX does not establish that a receiving party can suffer any level of reduction and still automatically obtain all of its assessment costs. CPR 47.20(3)(b) expressly requires the court to consider the reduction, and Senior Costs Judge Rowley described the approximate 40% MRO reduction as significant. It simply did not outweigh the fact that the claimants and MROs had prevailed on the main contested issues in this particular litigation.

So the safer proposition is that the size of a reduction is relevant to the assessment costs order, but it is not necessarily determinative of who was successful. That is materially different from saying a 40% reduction does not matter. It plainly can.

Evidence problems did not justify a second costs penalty

The judgment also contains a useful discussion about evidence. The MRO litigation had generated extraordinary evidential material: by the November 2025 hearing, 27 witness statements had been served for the claimant and MRO side and six witnesses gave oral evidence. The Defendants criticised limitations in that evidence, and Senior Costs Judge Rowley considered whether those limitations should also affect the costs award. He concluded they should not.

His reasoning was essentially that any weakness in the evidence had already affected the substantive decision. If there was sufficient evidence to support the conclusion reached, imposing a further reduction to the costs order merely because the evidence could have been better would risk penalising the successful party twice. If the evidence was actually insufficient to support the decision, that was a matter for the appeal. A deficiency which has already affected the substantive outcome does not automatically require a second penalty in costs — but this was fact-specific and should not be turned into a general immunity for poor evidence.

The Defendant won the disclosure application

The general result favoured the claimants. The earlier disclosure application did not. The Defendant in JXX had sought information about the MRO fees, and the court had required the claimant to elect whether to provide information about the MRO component or proceed with assessment of the medical disbursement without it. The claimant and MRO ultimately elected to provide evidence.

Senior Costs Judge Rowley regarded the Defendant as plainly successful on the thrust of that application. In particular, the eventual assessment required the MRO element to be separated from the experts’ own professional fees, which was what the Defendant had sought. The Defendant was therefore awarded the costs of that disclosure application. This is another reason the judgment should not be summarised as “claimants awarded all MRO costs”. They were not; the costs order followed the actual outcome of each discrete dispute.

The joinder applications went the other way

The MROs had been joined into the proceedings so that they could participate directly in the litigation concerning their charges. The reserved costs of those applications would ordinarily become costs in the case unless another order were made. Senior Costs Judge Rowley considered that to be the correct result and expressly awarded the costs of the joinder applications to the claimants and MROs. For the purposes of the proceedings, the judge treated the individual claimants and the MROs together as the successful parties.

Confidential disclosure: costs in the case

There had also been a confidential disclosure application resulting in an agreed confidentiality ring. The parties treated the costs involved as comparatively insignificant against the overall litigation. Senior Costs Judge Rowley concluded that costs in the case would have been the appropriate order and made that order. Its practical effect depends upon who ultimately remains the successful party following the pending appeals.

What about the MRO’s Part 36 offer?

There is a small but potentially useful Part 36 point within the judgment. MAPS had made offers concerning its fees. During the consequential hearing, it was accepted that the enhanced consequences under CPR 36.17(4) did not appear to apply to a party which was not itself bringing the claim, and the contention that those consequences applied to MAPS was withdrawn. That did not mean the offers were irrelevant; they could still be taken into account under the court’s wider costs discretion.

Claimant costs practitioners should therefore be careful not to collapse two questions: is this formally capable of producing CPR 36.17 consequences, and can the offer nevertheless be relevant when the court exercises its costs discretion? In JXX, the answer to the second remained yes.

The absence of Defendant offers did not change the costs order

The claimant side also criticised the Defendants for failing to make offers which could have resolved the MRO dispute. Senior Costs Judge Rowley did not give that criticism substantial weight. The court considered the tactical history of MRO litigation, including the risk that accepting an offer could have left the wider legal uncertainty unresolved. Neither the absence of Defendant offers nor the presence of claimant and MRO offers was enough to justify departing from the general costs order the court otherwise considered appropriate.

That should not be read as meaning offers do not matter. They plainly can. The point is that offers are one circumstance in the overall costs discretion, not an automatic answer divorced from the litigation context.

Why the court refused summary assessment

All advocates initially agreed that the consequential costs should be summarily assessed. Senior Costs Judge Rowley disagreed. The claimant-side costs were well into the hundreds of thousands of pounds, and the judge described summary assessment, based on relatively brief schedules and submissions, as necessarily a “blunt tool” or broad-brush exercise.

The costs were also many multiples above the £75,000 provisional assessment threshold under CPR 47.15. The court saw no obvious reason why parties claiming costs at that level should receive less detailed scrutiny simply because the costs order itself arose out of detailed assessment litigation. There were also specific issues still to determine, including significant challenges to the level of counsel’s fees. The court therefore ordered that the claimants’ costs be assessed on the standard basis by detailed assessment if not agreed.

That is a practical reminder that the fact a court can summarily assess substantial costs does not mean summary assessment will always be appropriate. Where the amount is very large and the challenges require proper examination, detailed assessment may be the fairer route.

Significant counsel fee challenges remain

The judgment gives one example of why a broad-brush assessment was unsuitable. In one of the cases, leading counsel represented both the claimant and the MRO. In the other, two leading counsel, one supported by junior counsel, represented the claimant and MRO interests. The Defendants made clear that the extent of those counsel fees would be challenged if they became liable for the costs.

Senior Costs Judge Rowley considered that kind of issue unsuitable for disposal through a brief summary assessment. Importantly, the September judgment therefore decides who is entitled to claim the costs. It does not decide how much of those very substantial counsel fees will ultimately be allowed. That distinction matters.

No payment on account

The claimant side also did not obtain a payment on account of the newly awarded costs. CPR 44.2(8) ordinarily requires the court to order a reasonable payment on account unless there is good reason not to do so. Senior Costs Judge Rowley found good reason here. All relevant parties were seeking some variation of the substantive MRO judgment on appeal, and the judge considered there to be a significant prospect that the costs orders could therefore be disturbed. The parties were commercial organisations able to await the appellate decision, and substantial disputes over counsel fees remained unresolved. Accordingly, no payment on account was ordered. Again, that is not a general rule for cases under appeal; it was the product of the unusual circumstances here.

The Court of Appeal still matters

The September costs judgment sits on top of a substantive decision which is itself under appeal. Senior Costs Judge Rowley recorded that all parties had been granted permission to appeal directly to the Court of Appeal. That is important when using either judgment today: the March 2026 decision remains significant first-instance authority from the Senior Costs Judge, but the final appellate position on MRO fees has not yet been determined.

What does this mean for claimant firms?

There are several practical lessons.

1. Do not assess success purely by percentage reduction. The court may need to look at what the paying party was actually arguing, what the receiving party established, which issues were won and lost, and what practical order resulted. A large monetary reduction can still coexist with success on the central legal issues.
2. But do not ignore a substantial reduction. Around 40% of the MRO element was reduced in HLA, and the court expressly treated that as significant. It simply did not consider it sufficient, on the facts, to justify reducing the general costs award. The reduction remains part of the CPR 47.20 analysis.
3. Separate discrete applications. The receiving party won the general MRO litigation but lost the disclosure application, and the costs followed those separate outcomes. That is important when analysing a long detailed assessment with several interlocutory disputes.
4. Evidence still matters. The claimant and MRO side ultimately succeeded despite criticism of aspects of its evidence, but that does not mean weak evidence is safe — the substantive judgment itself was shaped by what had and had not been proved.
5. Keep the expert fee and MRO fee identifiable. The Defendant won the disclosure application precisely because the MRO element needed to be capable of separation from the expert’s own professional fee. That remains a practical point for bills of costs, supporting invoices, Points of Dispute, Replies and detailed assessment preparation.
6. Do not assume a very large costs order will be summarily assessed. Hundreds of thousands of pounds, substantial counsel fees and discrete assessment issues may justify a full detailed assessment even when the costs themselves arise from earlier costs proceedings.

What does this mean for Points of Dispute?

There is also a useful drafting lesson. A paying party challenging MRO charges should distinguish entitlement to an MRO element at all, transparency of the MRO element, reasonableness of the mark-up, proportionality, the underlying expert’s own charge, and any separate funding or administrative argument. JXX demonstrates why collapsing everything into “medical agency fee excessive and irrecoverable” is too blunt. Likewise, a receiving party should not simply respond “MRO fee reasonable and maintained”. The March and September judgments show that different aspects of the same MRO invoice can produce different outcomes. Our guide to clinical negligence Points of Dispute and detailed assessment develops the point.

A 40% reduction is not the same as losing 40% of the case

This deserves repeating because it is likely to become the headline taken from the judgment. In HLA, the MRO charges were reduced by roughly 40%. But the costs dispute had involved wider questions about whether the Stringer Cap applied, whether administrative elements were recoverable, whether deferred payment and write-off features amounted to irrecoverable funding costs, what evidence was required, and how MRO charges should be assessed. The claimant and MRO side won most of those arguments, and the court therefore treated them as the successful parties despite the substantial reduction in quantum. That is why a detailed assessment costs order cannot always be decided by taking a calculator to the bill. The issues matter too.

What JXX [2026] EWHC 2404 does not decide

The new judgment should not be overstated. It does not decide:

• that a 40% reduction is irrelevant to costs;
• that receiving parties always recover assessment costs despite substantial reductions;
• that every MRO claimant is the successful party;
• that all MRO charges are recoverable;
• that a 25% mark-up is now binding appellate law;
• that disclosure of the MRO element is unnecessary;
• that Part 36 consequences automatically apply to MROs joined as third parties;
• that hundreds of thousands of pounds in counsel fees are reasonable;
• or that the substantive March 2026 judgment will survive the appeals unchanged.

The September decision is about the incidence and method of assessment of the costs generated by this particular litigation. Its wider value lies in the court’s approach to success, reductions, evidence, discrete applications, offers, summary versus detailed assessment, and payments on account.

Key takeaways from JXX v Archibald [2026] EWHC 2404

1. The claimants and MROs were the successful parties on the general MRO issues.
2. They recovered the general costs of those issues without a percentage reduction.
3. That remained the position despite an approximately 40% reduction to the MRO fees in HLA.
4. The size of the reduction was relevant, but it did not determine success.
5. The Defendant recovered the costs of the JXX disclosure application.
6. The claimants and MROs recovered the costs of the joinder applications.
7. The confidential disclosure costs were costs in the case.
8. The claimant-side costs, running into hundreds of thousands of pounds, will be subject to detailed rather than summary assessment if not agreed.
9. No payment on account was ordered while the appeals and substantial counsel-fee challenges remain outstanding.
10. The substantive MRO ruling is still under appeal, so the story is not finished.

How DMD Costs can help

DMD Costs assists claimant solicitor firms with the recovery of clinical negligence, personal injury and other standard-basis costs, including disputes involving medical expert evidence and MRO charges. We assist with bills of costs and Precedent S electronic bills, medical expert disbursements, MRO fee disputes, Points of Dispute and Replies, costs budgeting, proportionality, hourly rates, counsel fees, detailed assessment preparation and negotiation through to settlement.

The latest JXX judgment is a good example of why expert-fee disputes need to be separated into their component issues. A paying party can be right about one part of the challenge and wrong about another; likewise, a receiving party can remain successful overall even after a significant reduction. Our clinical negligence costs service covers expert and MRO fee disputes from the bill through to detailed assessment.

A percentage reduction tells you how much was allowed. It does not necessarily tell you who won the dispute.

Source: JXX v Scott Archibald and others [2026] EWHC 2404 (SCCO), Senior Costs Judge Rowley, handed down 18 September 2026, and the substantive decision JXX v Archibald II [2026] EWHC 630 (SCCO). Figures and quotations are taken from the approved judgments.