SolvedEIM11260 | Incentive award schemes: deductions from awards
From HM Revenue & Customs · Employment Income Manual
It’s unlikely that an employee who has received an incentive award will be able to justify a deduction from that award under section 336 ITEPA 2003. The conditions that must be met before a deduction can be permitted under section 336 are stringent and exacting, see EIM31630.
If an employee requests a deduction you should send the papers to the Incentive Award Unit, see EIM11240. The question may already have been considered there in discussions with the provider.