A single joint expert (SJE) is one forensic accountant appointed by both parties together and paid jointly. A party-appointed forensic accountant is instructed by one side only. Courts prefer SJE appointments in financial proceedings where the expert issue is relatively contained, but in complex disputes involving significant sums or contested methodology, party-appointed experts and a joint meeting under CPR 35.12 are more appropriate.
- What is a single joint expert in financial proceedings?
- What is a party-appointed forensic accountant and when is one appropriate?
- What we see in practice: how SJE appointments go wrong and when they save proceedings
- How does the court decide which type of expert to appoint?
- What are the cost implications of each arrangement?
- What happens when a party disagrees with a single joint expert's conclusions?
What is a single joint expert in financial proceedings?
A single joint expert is a forensic accountant appointed by both parties under a shared letter of instruction and paid for jointly from the outset. The SJE owes their duty to the court, not to either instructing party, and their expert witness report is served simultaneously on both sides and filed with the court.
The SJE model is the default preference of courts in England and Wales when financial expert evidence is genuinely needed and the expert issue is amenable to a single objective analysis. The procedural basis is CPR Part 35 and Practice Direction 35, which together establish that courts should wherever possible direct a single joint expert rather than permit each party to instruct separately. The overriding objective in CPR Part 1 underpins this preference: keeping proceedings proportionate and controlling cost.
In financial remedy proceedings under the Family Procedure Rules, the same preference applies. Where the court considers that expert evidence on, for example, the value of a business or the reconstruction of a director's loan account is necessary, the default question is whether an SJE can address it adequately. Only where the case complexity, the sums involved, or the genuinely contested nature of the methodology justifies two experts will the court permit party-appointed forensic accountants.
The SJE receives a single letter of instruction drafted jointly by the solicitors (or approved by the court where the parties cannot agree). Both parties may put written questions to the SJE under CPR 35.6 after the report is served. The SJE must answer those questions in writing, and those answers form part of the expert evidence before the court. Neither party can privately brief the SJE or instruct them to adopt a particular methodology: all communications are copied to both sides.
The SJE model works well when the expert issue is relatively self-contained, the underlying documents are agreed, and what is in dispute is the application of an accounting methodology to an agreed set of facts. It works less well, as discussed below, when the documents themselves are in dispute, when one party controls access to information, or when the financial complexity of the case is such that a single forensic accountant cannot adequately address all the issues within a proportionate scope of work.
What is a party-appointed forensic accountant and when is one appropriate?
A party-appointed forensic accountant is instructed by one side only and produces an expert witness report setting out that expert's opinion. Where both parties appoint their own expert, the court will usually direct a joint statement under CPR 35.12 identifying the areas of agreement and the areas that remain in issue, to be produced after a joint meeting of experts.
Party-appointed experts are appropriate in a number of circumstances that arise regularly in complex financial proceedings. First, where the value of the expert issue is sufficiently high that the cost of two experts is proportionate: a case involving a disputed business valuation with a range of £2 million to £8 million almost certainly justifies party-appointed experts. Second, where the methodology for calculating the loss or valuation is itself genuinely contested and requires adversarial expert analysis rather than a single objective view. Third, where one party does not trust the integrity of an SJE appointment, either because of concerns about how the letter of instruction will be drafted or because of past experience with documents being provided selectively to a shared expert.
In commercial litigation, HMRC investigations, and Proceeds of Crime Act confiscation proceedings, party-appointed forensic accountants are more common than SJEs because the financial complexity, the volume of documents, and the contested nature of the underlying facts frequently make a single appointment impractical. In POCA proceedings, the prosecution will instruct a forensic accountant to produce the benefit figure and available amount calculation, and the defence will typically wish to challenge both through their own expert. A single joint expert on those issues would rarely serve justice adequately.
Party-appointed experts must still comply with CPR Part 35 and their overriding duty is to the court, not to the instructing party. The fact that an expert is appointed by one side does not permit them to act as an advocate. The distinction between a party expert and an advocate is one that courts enforce firmly, and expert reports that read as submissions rather than objective analysis are routinely given reduced weight or excluded.
For a detailed overview of the expert witness role in financial proceedings, see our guide on the forensic accountant as expert witness, which covers the full scope of instructions, report requirements, and court obligations.
What we see in practice: how SJE appointments go wrong and when they save proceedings
From over 150 instructions as a forensic accountant expert witness in England and Wales, I have seen SJE appointments deliver real efficiency savings and I have seen them create serious procedural problems. The pattern of failure is consistent enough that solicitors instructing in financial remedy and commercial proceedings should recognise the warning signs before committing to a shared appointment.
The most damaging pattern is document asymmetry. In matrimonial finance proceedings, one party frequently controls a business and therefore controls access to the primary accounting records. When the SJE is appointed and the letter of instruction issues, the controlling party provides the business records to the expert. In a substantial minority of cases I have reviewed, those records are incomplete: management accounts are missing for specific periods, bank statements for one account are omitted, or board minutes authorising particular transactions are not disclosed. The SJE, acting in good faith on the documents provided, produces an expert witness report that reflects an incomplete picture. The other party then challenges the report, the court directs further disclosure, and the SJE must revisit their analysis. The savings from the SJE appointment are eliminated, the hearing is adjourned, and wasted costs applications follow. I have seen this pattern add between three months and eight months to proceedings in cases where the underlying financial dispute was not inherently complex.
The second pattern is questions drafted too narrowly. The letter of instruction to the SJE defines the scope of the expert witness report. Where solicitors draft that letter without adequate input from a forensic accountant, the questions frequently miss important issues. I have been shown SJE reports that address business net asset value but not maintainable earnings; that address turnover reconstruction but not the director's drawings pattern; that address the identified company but not associated entities held by the same beneficial owner. The SJE answers what they are asked and produces a court-compliant report. The issues that were not asked about are not addressed, and the parties discover this gap at a pre-trial review, by which point it is too late to reopen the instruction without significant cost and delay.
The third pattern is late instruction. SJEs are sometimes appointed after disclosure rounds have closed and within weeks of a final hearing. The expert is given insufficient time to review the documents properly, request clarification, and produce a considered report. Under time pressure, the analysis is necessarily less thorough. Courts increasingly recognise this problem and directions for expert evidence in financial proceedings now usually set a timetable for the SJE instruction, but where parties manage their own timetable in arbitration or in proceedings where directions have slipped, late appointment remains a real risk.
The Daniels v Walker [2000] principle confirms that a party who is dissatisfied with an SJE report is not without remedy: the court has a discretion to permit that party to instruct their own expert in addition, particularly where the sums at stake justify it or where the SJE report is shown to have significant limitations. Solicitors should be aware that Daniels v Walker is a fallback, not a substitute for getting the SJE instruction right at the outset. Exercising the Daniels v Walker discretion adds cost and delay, and courts will scrutinise whether the dissatisfied party has used CPR 35.6 questions adequately before granting permission to instruct a second expert.
When SJE appointments work well, they are genuinely valuable. Cases involving a single contested question, such as whether a specific inter-company transfer was a loan or a distribution, or what a small business was worth at a given date when the methodology is not seriously in dispute, are well suited to the SJE model. In those cases the saving in expert fees, the reduction in adversarial positioning between experts, and the cleaner presentation of evidence to the court all benefit the parties. The key is matching the complexity of the appointment to the complexity of the case.
How does the court decide which type of expert to appoint?
The court's decision on whether to direct an SJE or permit party-appointed forensic accountants is governed by CPR 35.7 and PD35, which require the court to consider whether the case calls for a single joint expert and to make that direction unless there is good reason not to. The factors the court weighs include the complexity of the expert issue, the financial value of the dispute, and whether the methodology is likely to be agreed or genuinely contested.
In practice, courts in the Business and Property Courts routinely permit party-appointed experts in commercial litigation where the financial sums and complexity justify them. In the Family Court, the starting position is an SJE preference, but courts will permit party-appointed experts in higher-value or more complex cases. Judges increasingly ask parties at case management conferences to justify why an SJE is not appropriate rather than why one is needed: the presumption in favour of the SJE is strong and must be rebutted with specific reasons.
Where the parties disagree about whether an SJE is appropriate, the court decides. Relevant factors include: whether the expert issue involves contested methodology (favouring party experts); whether both parties have equal access to the underlying documents (favouring SJE where access is equal); whether the cost of two experts is proportionate to the sum in dispute (favouring SJE in lower-value cases); and whether one party's position is that the expert evidence should not be admitted at all (a separate question from the SJE versus party-expert choice).
Courts have become increasingly rigorous about proportionality since the costs management regime under CPR Part 3 was extended. Where the expert costs budget for two party-appointed forensic accountants is a significant fraction of the amount in dispute, courts will direct an SJE even in moderately complex cases, on the basis that proportionate justice requires controlling costs. Solicitors should factor this into their advice to clients before incurring the cost of preparing for a party-expert appointment that the court may not permit.
What are the cost implications of each arrangement?
The cost of a single joint expert is shared equally between the parties as a default, though the court can and does vary this in appropriate cases, for example where one party caused significant additional work through delayed disclosure or inadequately drafted questions. The typical SJE instruction for a business valuation or loss quantification in straightforward proceedings costs between £5,000 and £20,000 in expert fees, depending on complexity, document volume, and whether the expert gives oral evidence at trial.
Two party-appointed forensic accountants cost more in total expert fees: each expert's individual instruction may be comparable to an SJE's fee, and where both produce full reports and attend a joint meeting, the combined expert cost typically runs between £15,000 and £60,000 or more for complex instructions. The party-expert model also generates additional costs in the form of the joint meeting itself, production of the joint statement, and potentially oral evidence from both experts at trial.
However, the apparent saving from an SJE appointment can be illusory if the instruction is poorly managed. An SJE who is given incomplete documents and must revisit their analysis may cost as much as two well-managed party experts. An SJE report that is successfully challenged under Daniels v Walker, leading to a second expert being permitted, will cost more than two party experts from the outset. The real cost comparison is between a well-managed SJE appointment and a proportionate party-expert instruction, not between the theoretical costs of each model.
Where costs are recoverable from the other side, the winning party will usually recover a reasonable proportion of their expert costs. In matrimonial finance cases where there is no order as to costs as a starting position, the choice between SJE and party expert has a direct impact on what each party pays out of pocket regardless of the outcome. Solicitors should advise clients on both the absolute cost and the recoverability risk when discussing expert appointment strategy.
For cases involving business interruption quantum or complex financial loss, see our service page on business interruption claims for how forensic accountant instructions in those matters are typically structured and costed.
What happens when a party disagrees with a single joint expert's conclusions?
A party who disagrees with an SJE's conclusions has three procedural options. First, they can put written questions to the SJE under CPR 35.6. Questions must be proportionate and must seek clarification rather than require the SJE to reconsider their methodology or produce additional analysis. The SJE's written answers form part of the evidence and may resolve the disagreement or clarify the limits of the expert's opinion.
Second, the party can apply to the court under the Daniels v Walker [2000] principle for permission to instruct their own expert in addition to the SJE. The court will grant this where the party can demonstrate good reason: the sums at stake justify a second opinion, or the SJE's report has a specific methodological limitation that the CPR 35.6 questions have not resolved. Daniels v Walker is not a mechanism for parties who simply dislike the SJE's conclusions: the court will require a substantive basis for the application.
Third, in exceptional cases, a party can challenge the admissibility or weight of the SJE's report on grounds that go to the expert's independence, methodology, or compliance with CPR Part 35. This is a high bar and is rarely successful where the SJE has followed the correct procedural steps. However, where an SJE has adopted a clearly incorrect methodology or has failed to address a material issue, a submission on weight at trial may be more appropriate than a Daniels v Walker application.
Solicitors should note that the CPR 35.6 questions route must be used before a Daniels v Walker application is made. Courts expect parties to have exhausted the written questions mechanism before seeking permission for a second expert, and an application made without adequate use of CPR 35.6 will be looked at sceptically.
Frequently asked questions
Can SJE conclusions be challenged at trial?
Yes. The SJE's report is evidence, not a binding determination. A party can submit at trial that the report should be given limited weight, cross-examine the SJE on their methodology, or argue that the court should reach a different conclusion on the expert issue. However, successfully challenging an SJE report at trial is difficult if the expert has followed correct methodology and complied with CPR Part 35. The Daniels v Walker route, applied before trial, is usually more effective than a challenge at the hearing itself.
What questions can be put to an SJE under CPR 35.6?
Questions under CPR 35.6 must be for clarification of the report only. They cannot require the SJE to carry out additional analysis, review documents not originally provided, or change their methodology. Questions seeking elaboration on specific reasoning, requests to confirm or clarify assumptions, and requests to explain the basis for a specific figure are all permitted. Questions that amount to cross-examination or that seek a rewrite of the report will not be answered and may attract a costs order if unreasonably persisted with.
Is an SJE cheaper than two party-appointed experts?
On paper, yes: one set of expert fees is less than two. In practice, the saving depends on how well the instruction is managed. An SJE who must revisit their analysis due to incomplete documents, or who is subsequently supplemented by a Daniels v Walker expert, may cost as much as two proportionately scoped party experts. The cost advantage of the SJE model is real only where the instruction is properly prepared, the letter of instruction is comprehensive, and both parties provide complete disclosure from the outset.
Can I instruct my own expert if I disagree with the SJE?
Yes, but only with the court's permission under the Daniels v Walker [2000] principle. Permission is not automatic and will not be granted simply because a party dislikes the SJE's conclusions. The court will require a substantive basis: the sums justify a second opinion, or the SJE's report has a specific limitation that written questions have not resolved. CPR 35.6 questions should be exhausted first. A well-founded Daniels v Walker application, supported by specific identified deficiencies in the SJE report, stands a reasonable prospect of success.
What happens if the SJE is given incomplete financial records?
The SJE must work from the documents provided and should note any material gaps in the report. Where documents are provided by one party and appear incomplete, the SJE should report this to both parties and to the court. The court can then direct further disclosure. A report produced on incomplete records should identify the limitations of the analysis and the specific documents whose absence affects the conclusions. Solicitors should ensure that document disclosure is complete before the SJE instruction issues, not after the report is received.
The choice between a single joint expert and party-appointed forensic accountants is one of the most consequential procedural decisions in financial proceedings involving expert evidence. Courts default to the SJE model for proportionality, but in cases involving significant sums, contested methodology, or document access concerns, party-appointed experts with a joint statement process under CPR 35.12 will produce a more reliable and more complete picture for the court. From over 150 instructions, the clearest lesson is that a well-prepared SJE instruction, with a comprehensive letter and complete document disclosure from both parties, saves time and cost. A poorly prepared SJE instruction creates the illusion of efficiency while generating the delays and wasted costs of a contested process.
If you are a solicitor considering how to structure expert evidence in financial proceedings, contact Key Ledgers to discuss the instruction at Key Ledgers enquiry page or call 020 8907 9218.
Author: Bharat Varsani FCCA, CPR Part 35 qualified forensic accountant expert witness, 150+ instructions in England and Wales.