The general purpose of the UK's Controlled Foreign Company (CFC) rules is to prevent UK companies from using a subsidiary, based in a low or no tax jurisdiction, to avoid taxation in the UK. In particular, they allow the UK tax authorities to reallocate all profits artificially shifted to an offshore subsidiary back to the UK parent company, where it can be taxed accordingly. CFC rules in general are an effective and important feature of many tax systems to address tax avoidance.