The binding of antibodies by Fc receptors promotes many effector immune responses, including phagocytosis and antibody-mediated cell cytotoxicity. The Fc receptor-like (FcRL) family comprises six proteins that are homologous to the high-affinity Fc receptor for IgG (FcγRI), but their ligands were unknown. This study has shown that human FcRL4 and FcRL5 (which are expressed by activated and memory B cells) are receptors for IgA and IgG, respectively. FcRL5 bound to all human IgG subtypes, showing the highest affinity for IgG1 and IgG2. As FcRL4 and FcRL5 recruit the inhibitory protein tyrosine phosphatase SHP1, they are likely to negatively regulate immune responses. Notably, FcRL4 is the first inhibitory receptor to be described for IgA. The authors suggest that blockade of FcRL4 and FcRL5 could be used in vaccines to augment immunity to pathogens or tumour cells.