New Institutional Economics treats early modern Spain as an example of a state whose political and contracting institutions hindered economic growth. However, the assumption that Spanish political institutions were predatory in this respect has been called into question. This paper challenges the idea that Spain was unable to develop sufficiently good contracting institutions, of which we know relatively little. Using data from Malaga's notarial credit market, I show that legal institutions facilitated contractual compliance in private financial transactions. Specifically, public mortgage registries, which had improved the registration of properties used as collateral since their creation in 1768, favoured the subscription of larger contracts. Furthermore, results suggest that registries could have contributed to the development of a more impersonal credit market.