Mercury in the 7th house (Yuvati / Kalatra, the house of marriage) brings the significations of Mercury, namely intellect & analysis, communication & speech, business & trade, into the area of marriage, the spouse, partnerships and one-to-one relationships. The 7th house governs marriage & spouse, partnerships, business dealings, passion & desire.
Results of Mercury in the 7th House
Mercury is a neutral planet, so here it tends to bring poor communication, indecision, nervousness and trouble in studies or trade focused on marriage, the spouse, partnerships and one-to-one relationships. As an angular (kendra) house, this placement strongly shapes the overall life direction.The exact result depends on which sign Mercury occupies here and the aspects it receives.
When It Activates
These results typically surface during the Vimshottari mahadasha or antardasha of Mercury, and when transiting planets trigger the 7th house. A well-placed Mercury here supports a fulfilling marriage, strong partnerships and good business alliances; when afflicted it can indicate marital discord, broken partnerships and difficulty with the spouse.