Many debt planning exploits mismatches between tax regimes. A typical hybrid instrument is debt for the payer but equity for the recipient. A hybrid entity is opaque in one jurisdiction but transparent in the other. The OECD proposals counteract this by either denying the deduction or taxing the receipt. The UK plans to introduce the rules by 2017. They contain no motive test and the thresholds for applications are worryingly low. Issues relating to CFC inclusion and hybrid regulatory capital remain unsolved. Companies should act now to refinance, recognising that fewer and fewer tax effective structures for cross-border debt remain.