A:AnswerDear customer, thank you for your question.
Every Panasonic unit can be extended to a maximum of 6 handsets. This model has 4 and you can add 2 more. The additional handset for your model is KX-TGEA40 .
A:AnswerThank you for reaching out. Please find more information about this feature here: https://help.panasonic.ca/viewing/ALL/KX-TGE432/OI/TGE432_PNQX7786WA/TGE432_PNQX7786WA.pdf#page=19