PAYE for overseas employers with no UK presence

Many people work in the UK on an ongoing basis but are employed by foreign enterprises – foreign companies without any formal presence in the UK or foreign embassies for example. So what obligations – if any – arise for such foreign enterprises from a UK perspective with regard to the deduction of income tax and National Insurance contributions under the PAYE system? Do such enterprises need to register for PAYE and National Insurance? And if so under what circumstances? Further are there any obligations for employees? What are these and when would they apply?

The position for employers

The obligations for employers can depend upon a number of factors and the answers to questions including:

a) Is there a UK subsidiary? Has a permanent establishment (or similar taxable presence) been created in the UK?

b) Is the overseas employer based in the EU? Here the...