A:Answer I would be happy to assist you with verifying whether or not you are able to use multiple handsets with one base. The model that you provided via your link, model # KX-TGA101S, can expand to more than 1 handset with one base. However, the model that you mentioned in your actual question, model # KX-TGA401 also can be expanded to multiple handsets with 1 base. I am attaching a link of the manual for this model. Pages 5 and 6 provide the instructions to register each handset with your main base unit.
http://bit.ly/W8JhwL