Translocations to areas free of introduced predators (offshore islands, mainland fenced exclosures) have become a key management action for conserving Australian mammal species, many of which are highly vulnerable to predation by introduced foxes and/or cats. Multiple safe havens create multiple safe havens, further reducing the risk of extinction. However, creating safe havens is expensive, with an ongoing legacy of maintenance and biosecurity. Consequently, the safe haven approach is broadly viewed as an emergency intervention used to secure species from extinction. To date, the existing safe haven network is highly decentralised where conservation agencies have created safe havens independently of one another. Consequently, species representation is highly disproportionate, with some species are represented in several safe havens, and other species in none. Creating new safe havens strategically could rectify unequal representation, ensuring a minimum level of security for all threatened taxa vulnerable to foxes/cats, while minimising the number of costly new projects. In an Australia-wide prioritisation for creating new havens, we identified 106 taxa whose persistence strongly depends on representation within safe havens. We assessed the vulnerability of each taxon to foxes/cats, and characterise their current population structure. Potential new safe havens were prioritised based on the expected reduction in extinction risk across the suite of threatened species, improving representation within the network with a minimal number of new fences. This approach provides a tool for assessing the merit of new additions to Australia's safe haven network, pursuing the dual goal of minimal cost and improved representation.