Access to social protection differs widely among international migrants. This article focuses on the issue of earnings-related contributions to social security programmes and their (frequent) lack of portability across borders — a problem that particularly affects South-South migrants. Furthermore, attention is drawn to the fact that in many low-income countries a lack of administrative capacity in the operation of social security programmes is often, in the first instance, a greater problem than the lack of portability of any potential earned rights to cash benefits provided under them. Commonly, the inability of migrants to benefit, both from social security programmes that are in place in the country of origin and in the host country detracts significantly from the well-being and security of migrants and their families. The article concludes that South-South migration must be understood as being significantly different from North-North migration, where social protection issues are much more tractable.