Kenton v Slee Blackwell [2023] EWHC 2613 (SCCO)

Senior Costs Judge Gordon-Saker found that providing a ‘hopelessly inaccurate estimate’ and an inadequate risk assessment regarding a success fee will result in the claim for costs against the client being decreased significantly.


In Kenton v Slee Blackwell [2023] EWHC 2613 (SCCO), the Claimant sued her previous solicitors who had acted for her in a professional negligence claim against another firm, ABC. They had entered into a Conditional Fee Agreement (CFA) in May 2018, with a success fee of 80% if the claim concluded before trial and 90% if it concluded at trial. After mediation, ABC agreed to pay Kenton’s costs in the sum of £138,000.

Slee Blackwell, subsequently, sent Ms. Kenton a bill which amounted to approximately £342,000, where approximately £90,000was payable to the Claimant after damages.

The Defendant’s did not adduce their own evidence or cross-examine Ms Kenton’s witness statement.

But this raised numerous concerns and questions by the Claimant as she had relied on the estimates provided by the Defendant’s, as well as the success fee outlined in the CFA. Judge Gordon-Saker addresses the two key issues of: reliance on costs estimates, and the risk assessment in creating the success fee. This blog will explore his reasoning and decision in turn.

Costs Estimate

Ms Kenton clearly relied on the estimates provided by the Defendant; it was one of the reaons why, she decided to proceed with them to act on her behalf. Slee Blackwell’s estimates outlined as follows:

£5,000 to £20,000 if settlement was reached before issuing of proceedings.
£30,000 to £50,000 if the case went to a contested hearing.

In addition to the above estimates, Slee Blackwell’s Ms Slade also explained how she was ‘yet to have a single case where [her] basic fees have been £100k […] the closest is £85k with a fully contested trial’. So, it was expected, from the Claimant’s point of view, that fees would not exceed this, especially since the case settled prior trial.

Unfortunately, the reliance on the estimates by the Claimant was heavily disputed by the Defendants, claiming that it would have been ‘unreasonable’ as it would not have accounted for the ‘unanticipated work required in considering the documents from ABC’. They argued that Ms Kenton did not complain about the original estimates after the costs exceeded £100k as per the costs spreadsheets that were sent to her 5 times over the period of the claim.

However, Judge Gordon-Saker found in the Claimant’s favour that the estimate was ‘inadequate’ and ‘a reasonable estimate of profit costs would have been about £50,000 before issue of proceedings’– not between £5,000 and £20,000. The Defendant’s did not provide a reason as to why the costs far exceeded the estimate and the Judge deemed it would be ‘reasonably expected for [the client] to pay a figure close to the estimate upon which she relied’’. He also added how the Claimant did not have the opportunity to ‘do something different’ as she had already signed the CFA and knew she would ultimately be liable if she tried to terminate it- ‘she could not escape it’. Therefore, £40,000 was the sum that the Claimant was expected to pay.

Success Fee

A risk assessment was carried out by the Defendant’s, which justified the success fees of 80% or 90% (as explained above). Mr Brighton, for the Defendant’s, argued to the Court that the success fees were reasonable and in accordance with the uncertainties involved and was given to the Claimant in an informed manner, to which she had approved. The Claimant contended this line of reasoning by stating these fees were unreasonably high.

Judge Gordon-Saker also agreed with the Claimants in this issue in that the risk assessment was ‘lacking’ and, therefore, there was no informed approval of the Claimant in accordance with CPR 46.9 (3) and (4). He points to paragraph 37 from Herbert v HH Law Ltd [2019] EWCA Civ 527 where informed approval means “that the approval was given following a full and fair explanation to the client” and Judge Gordon-Saker clearly states that the assessment was not a ‘proper assessment of the prospects of successes.’  The risk assessment that would be deemed reasonable and realistic would have generated a success fee of 50% of the basic charges; which was the final decision of the Court in this matter.


This case emphasises the importance of informed communication with the client, alongside the significance of correctly estimating figures and costs as the figures produced and presented to the client could be the last factor that contributes to the client’s decision in proceeding with the case. Solicitor’s should set out all estimates and charges in a clear format and any risk assessment’s should be undertaken with all factors of the case considered. 

Ujjaini Mistry is a Paralegal in Clarion’s Costs and Litigation Funding Team. You can contact her at or on 07436033368.

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