An access point (AP) device determines a set of basic service set identifiers (BSSIDs). Each BSSID includes a same group of most significant bits (MSBs) and a different group of n least significant bits (LSBs). The AP device assigns respective BSSIDs from the set of BSSIDs to multiple virtual APs, and designates one of the assigned BSSIDs as a reference BSSID that corresponds to a transmitter address (TA) for frames intended for client stations associated with more than one virtual AP. The AP device generates and transmits a management frame that includes i) a header with a TA field set to one of the assigned BSSIDs, and ii) a frame body with a plurality of fields that includes a) a first field set to n, and b) a second field set to the n LSBs of the reference BSSID. The TA field, the first field, and the second field in the management frame indicate the reference BSSID to a client station that receives the management frame.