When a family goes away for Shabbat, the hosts’ home is considered their home on that Shabbat. Thus, the guests should buy a share in the host’s candles for a pruta, which allows them to fulfill their obligation through the host’s lighting. According to the Ashkenazic custom, it is still preferable for the guests to light their own candles with the berakhot. If the family is staying in a separate residence, according to all customs it is proper for them to light there with the berakhot.
On Saturday night, if the guests plan to return home quickly, it is best for them to wait to light candles at home. If they plan to get home so late that people will no longer be walking on the streets, it is preferable that they fulfill the mitzva the same way they did on Friday, either through their host’s lighting or in the separate residence. If they are not returning home immediately but will still arrive home before it is too late, they may choose where to light. From the perspective of the previous day, their place is in their hosts’ home; but from the perspective of the upcoming day, their place is in their own home. Therefore, they may choose where they wish to light. 17

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