Family discount group
家族割・家族割引グループ kazokuwari / kazoku waribiki gurūpu
A registered group of eligible family lines used for discounts, free group calls or shared benefits; it is not always the same as a single household or a combined bill.
The accepted family range, proof, address rules and benefits differ by carrier. Some carriers accept relatives living separately or partners supported by specified documents. A discount group, a representative line, a combined-billing group and the actual user registration can be separate settings.
For a shop procedure, take proof of relationship when the address or surname does not make the relationship clear. Ask whose consent is needed, which line becomes representative, when the discount begins, and what happens if one member ports out.