There have been many debates on this area to the extent that HMRC has issued specific guidance. In relation to debt transfer, there is no obligation to check, assess or validate any contractors chosen provider where you had no involvement in them making that selection.
There are however some best practices we would encourage you to adopt so that you are able to clearly demonstrate this fact if required. This specific guidance is available to our members.
You will still have obligations under other legislation and you should ensure you fully consider your position in relation to offshore providers.