Globally, the outsourcing of services for drug development and commercialisation is increasing. Regulatory services are often included in this, and regulatory activities are increasingly the subject of specific, dedicated FSP (functional services partnership) projects. This article overviews a number of the more common models, including cost models, that can be deployed for the outsourcing of regulatory services. We assessed the appropriate criteria and advantages of these models, illustrating with examples from our experience. Interestingly, over the life of a single project, different models may be used, depending on a number of factors and aimed at maximising the benefits to both the supplier and the recipient of these services.