BIM100375 | Sale of income by an individual in exchange for capital: deduction of tax from payments
From HM Revenue & Customs · Business Income Manual
Non-residents as well as residents may be liable under the sale of income legislation but only if the occupation (see ) is carried on wholly or partly in the UK.
Where a capital amount is payable to a non-resident, HMRC may direct that Income Tax must be deducted on payment, the payer accounting to HMRC according to the ordinary procedure.