Your children travel for free if you either hold the Swiss Family Card, or the Junior Card. The Swiss Family Card is complimentary if you buy the Swiss Half Fare Card.
If you hold the Swiss Family Card or the Junior Card, you are not required to purchase tickets for the children. The card is their ticket when accompanied by at least one parent holding a valid ticket. Simply buy tickets for the adults. The Children Day Pass is required if you neither hold one of the two before-mentioned cards.
Swiss Family Card | Schweiz Tourismus (myswitzerland.com)
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