If a married man goes alone on Ĥanuka to visit friends or family while his wife remains at home, his wife must light the candles, and this exempts him from lighting. Nevertheless, even though he fulfills his obligation to light, some maintain that he does not fulfill his obligation to publicize the miracle and to see the candles. Therefore, he should hear the berakhot and see the candles in his hosts’ home or in the synagogue in order to participate in thanking God for the miracle (as explained above, ch 12 n. 6).
If the married guest wishes to light candles himself, according to Ashkenazic custom he may do so with the berakhot, but he should try to light before his wife lights at home. According to Sephardic custom, he should not light.
If he is staying in a hotel or in an empty apartment, even if his wife is lighting candles at home, he should light where he is. According to Ashkenazic custom, he should recite the berakhot; according to Sephardic custom, if he is in Israel he should not recite the berakhot, while if he is abroad he should recite them.
A married soldier on reserve duty does not need to light candles, as his wife is lighting on behalf of both of them at home. He should hear the berakhot from a different soldier who is lighting. If no one on the base is lighting, he should light in the mess hall with the berakhot. Even if he follows Sephardic custom, in this case it is a mitzva to light candles for the rest of the unmarried soldiers. If everyone at the base is observant, married, and has someone lighting at home on his behalf, the above does not apply. Nevertheless, in such a case, if there are ten people present, they should light candles at the base’s synagogue with the berakhot.
The law that a married man fulfills his obligation through his wife’s lighting applies as long as she remains at home. However, if she is a guest elsewhere (for example, in her parents’ home), her husband is once again obligated to light. In such a case, according to all customs he must light where he is with the berakhot.
Similarly, if a woman is away and her husband is lighting at home, she fulfills her obligation through his lighting. She should try to be present when her hosts light candles at their home. If she is alone in a hotel, she should light candles herself. According to Ashkenazic custom, she should recite the berakhot; according to Sephardic custom, she should not.
. According to Mordechai, Orĥot Ĥayim, and R. Yitzĥak Aboab as cited in sa 673:3, if a Jew is in a place where no candles are being lit, he must light with the berakhot. This is because there are two aspects to the obligation of lighting Ĥanuka candles: the personal obligation to light and the obligation that candles be lit in one’s location. If no one is lighting candles in one’s location, then even though his personal obligation has been fulfilled through his wife’s lighting, the obligation on his location requires him to light with the berakhot. However, according to Sephardic custom he should not recite the berakhot. This is because some maintain that one fulfills his obligation completely with his wife’s lighting, and we refrain from reciting berakhot in cases of uncertainty (Kaf Ha-ĥayim 677:23). In contrast, according to Ashkenazic custom he certainly must light with the berakhot. This is because even when one’s host is lighting, many light on their own with the berakhot, as described in the previous note. Here the case for doing so is even stronger, since some maintain that he is obligated to light.