PAYE: special type of payer or payee: employee of a non-UK employer
Section 689 ITEPA 2003
Where an employee works for someone in the UK but is employed and paid by an employer outside the UK the person in the UK for whom the employee works is treated, for the purposes of the PAYE regulations, as making any payments of or on account of PAYE income.
The UK person is required to operate PAYE on awards of readily convertible assets in the same way as on cash.
For further guidance see EP8077.