In the face of relentless and growing pressure for efficiency, companies are increasingly outsourcing to suppliers and contractors, meaning that managing safety across the supply chain is more challenging than ever. Guaranteeing safety throughout this chain is becoming more influential in decisions of who wins bids for major contracts and, beyond any human, economic and legal losses, just one major contractor accident can ruin a brand. Based on our extensive experience, in this paper we look at how culture-based approaches can strengthen control of safety in the supply chain, reducing reliance on conventional contracting approaches.