Can I avoid ir35 by using an offshore company for work outside of the UK?
If any combination of (a) the worker being resident, ordinarily resident or domiciled outside the United Kingdom, (b) the client being resident or ordinarily resident outside the United Kingdom, or (c) the services in question being provided outside the United Kingdom, the worker would not be chargeable to tax under Schedule E anyway. Therefore you can do this using a UK company and there is no need for an offshore company to escape IR35.