Follicular dendritic cells (FDCs) promote adaptive immune responses by retaining and presenting antigens to B cells in the lymph nodes, but it has been unclear how FDCs are able to retain antigens for such long periods of time. Heesters et al. show that FDCs express complement receptors and that they use these to acquire complement-coated immune complexes from non-cognate B cells. Having internalized these complexes, FDCs retain the immune complexes in non-degradative cycling compartments. The complexes are periodically recycled to the cell surface of the FDCs and become available to cognate B cells. The authors suggest that this pathway could also be used to share antigens between neighbouring FDCs.