EIM32560 | Other expenses: employment agency fees
From HM Revenue & Customs · Employment Income Manual
Fees paid by an employee to an employment agency for obtaining a job are not deductible under Section 336 ITEPA 2003.
The leading case is Shortt v McIlgorm (26TC262). A deduction was refused for a payment made to an employment agency. The payment was not made in the performance of the duties of the employment, see EIM31650.