On 7 August 2026 Mr Justice Garnham, sitting with Master Brown as an assessor, delivered the costs judgment following the generic issues trial in the military noise-induced hearing loss litigation: Abbott and others v Ministry of Defence [2026] EWHC 2083 (KB). The MoD must pay 60% of the claimants’ costs of the generic issues and the two test cases, with an interim payment of £2,515,194.95.
The headline figures have been widely reported. The more useful part of the judgment for claimant costs practitioners is why the interim payment came in at 50% rather than the 65% sought — and that reason is about costs documentation, not about the merits.
What the court actually ordered
The claimants sought 95% of their common costs of the trial generic issues and the lead cases, plus a payment on account of £6,013,822.09 and interest. The MoD resisted any order, arguing the outcome was “genuinely mixed” and that it had been the more successful party.
The judge ordered 60%, to be assessed on the standard basis if not agreed.
The arithmetic, step by step
This is worth setting out precisely, because the calculation has more stages than the headline suggests and the 60% is applied to a net figure:
- Gross common costs, as calculated by the claimants: £9,738,983.15
- Less the payment on account already received: £1,355,000
- Net figure: £8,383,983.15
- 60% of the net figure, being the costs of the generic issues determined by the judgment including the two test cases: £5,030,389.89
- Interim award of 50% of that sum: £2,515,194.95
The judge invited submissions on the final form of order and said he would receive further submissions on the mathematics if the figures were not agreed. The amount remains to be assessed.
Why 60%
The judge concluded that the claimants were very largely successful on the major issues — those that “attracted most attention and required most work in the trial”, namely the foundational concepts, the diagnostic method and the quantification method — and that they won damages in the two test cases.
The MoD was largely successful on the utility of military audiometry, latency, acceleration and cochlear synaptopathy, and on loss of future earnings so far as that issue was tested. Sixty per cent reflects that division rather than any criticism of conduct: the judge saw “no impropriety on the part of any person involved”, subject to a separate application concerning one expert.
The costs-documentation point — the practical lesson
The claimants asked for 65% of the appropriate figure by way of interim payment. They received 50%. The judge explained the difficulty directly:
“A difficulty I and Master Brown have faced in this case, despite our raising the matter during the hearing, is the absence of a signed draft bill or a certified statement of costs or a certified schedule of costs. I have real concerns about the costings we have received generally but particularly as regards the hourly rates claimed, the total number of hours claimed, the seniority of the solicitor engaged on some of the tasks involved, the appropriateness of the levels of delegation adopted and the disbursements.”
Because of that, the judge had to make “a broad brush estimate of what is likely to prove recoverable on a detailed assessment” and adjust it “to allow for a margin of error”. In litigation running a decade, with a lengthy and complex trial and a cohort that may reach 100,000 service personnel, the absence of certified costs documentation cost the claimants fifteen percentage points on the payment on account.
That is the transferable point. On any substantial application for a payment on account, the quality of the costs evidence put before the court is doing real work. A signed draft bill or certified schedule, defensible hourly rates, a clear explanation of who did what and why, and properly evidenced disbursements are not administrative tidiness — they directly affect what the paying party has to fund now rather than after assessment.
The indemnity principle and the discontinued claims
Two points arose that will matter in other cohort litigation.
On the indemnity principle, the court was shown the CFAs in the two test cases and given evidence about the wider arrangements between the claimants and their solicitors. The judge was satisfied that, to the extent an order for costs was made, the claimants are liable to their solicitors for the costs incurred on the generic issues.
On discontinuance, the judge accepted that the discontinuance of some claims within the cohort is a relevant factor. But applying Ho v Adelekun [2021] UKSC 43, for claims issued before 6 April 2023 QOCS applies and, absent proof of fundamental dishonesty, the defendant cannot recover its costs of the discontinued proceedings by way of set-off. The judge also recorded that the possibility of further discontinuances following his judgment was a matter he had regard to in exercising his discretion.
What this does not decide
- It does not fix the amount. The 60% order is a liability order; the sum falls to be assessed on the standard basis if not agreed.
- It does not determine the costs of individual claims in the cohort. This concerns the common costs of the generic issues and the two test cases.
- It does not close the door on further interim payments. The judge noted it will be open to the claimants to seek a further interim costs certificate if appropriate.
- The final form of order, and the mathematics if disputed, were left for submissions.
Checklist for claimant firms holding MoD NIHL files
- Treat certified costs documentation as a substantive part of any payment-on-account application, not a formality — the judgment shows what happens when it is missing.
- Be ready to justify hourly rates, total hours, fee-earner seniority and the level of delegation on each task. Those were the four specific concerns identified.
- Evidence disbursements properly, with instruction, invoice and rationale on the file.
- Keep common costs and individual claim costs clearly separated in your time recording, so a generic-issues order can be applied without argument about what falls inside it.
- For pre-6 April 2023 claims, check the QOCS position on any discontinued matters before conceding a set-off.
- Re-read the substantive judgment alongside this one — see our guide to the costs consequences of the Abbott judgment for MoD NIHL claims and our note on recovering costs after a Matrix settlement.
DMD Costs prepares and negotiates MoD NIHL costs for claimant solicitor firms — bills and electronic bills, Points of Dispute and Replies, payment-on-account applications and negotiation to settlement.
Source: Abbott and others v Ministry of Defence [2026] EWHC 2083 (KB), Garnham J sitting with Master Brown as an assessor, handed down 7 August 2026. Figures and quotations are taken from the approved judgment.