These are synastry overlay interpretations for Mercury in the partner’s 7th, 8th, 9th, 10th, 11th and 12th houses. (See instead Mercury overlays in 1st–6th houses.)
Mercury in 7th House Synastry Overlay
If your Mercury is in your partner’s seventh house of a synastry overlay, you sense that the house person will accept the way you think. This puts you at ease and makes it easy for you to communicate with them.
Your partner feels comfortable in your presence. They easily slide right into open and intimate conversation with you.
This overlay creates strong, open lines of communication between you that grow, rather than diminish, with time. You have an intellectual bond.
Mercury in 8th House Synastry Overlay
If your Mercury is in your partner’s eighth house of a synastry overlay, your words cut deep into your partner’s psyche. Be careful, as you don’t want to cause permanent damage with the things you say. You are prone to dominating the conversation, perhaps out of fear of being taken advantage of.
You partner doesn’t take your words lightly. They understand that you mean business when you talk. They are careful to respond correctly to you with calculated responses.
With this overlay, communication between you always tends to get serious and deep, quickly. Your communication is very clear and precise. This is useful for co-workers or students that have to work together. In relationships, this overlay makes you both prone to steering the conversation to serve your own purpose.
Mercury in 9th House Synastry Overlay
If your Mercury is in your partner’s ninth house of a synastry overlay, you find yourself talking a lot about travel, culture, and philosophical things.
Your partner can be impressed with everything you seem to know. They’re open to learning from you. They look forward to experiencing the things you talk about. You give your partner a greater perspective on life.
Mercury in 10th House Synastry Overlay
If your Mercury is in your partner’s tenth house of a synastry overlay, you may find it difficult to come up with something to talk about besides your goals and your career. This is not really negative (your partner doesn’t really mind all this talk of work), but you’ll have to work overtime to come up with a topic of conversation that doesn’t focus on work.
Mercury in 11th House Synastry Overlay
If your Mercury is in your partner’s 11th house of a synastry overlay, you’re immediately drawn to be open and communicative with them. You see your partner as a natural companion who will accept your ideas. Your style of communication is friendly and undemanding.
Your partner welcomes your lighthearted, upbeat style. Your partner finds you pleasant and looks forward to communicating with you.
This overlay makes your relationship warm and easy. You’re tolerant and patient with each other. This is a fertile environment that allows your relationship to grow. This placement of Mercury is valuable for marriages and for best friends.
Mercury in 12th House Synastry Overlay
If your Mercury is in your partner’s 12th house of a synastry overlay, you may have E.S.P. regarding your partner. You can probably sense clearly what they’re thinking. You may even understand things in their subconscious — things that even they don’t get about themselves. Because you’re sensing so much, you may feel overwhelmed around your partner.
Depending on your partner’s individual preference, they may or may not be comfortable with your ability to peer right into their subconscious. Your partner can, obviously, feel violated. This would compel them to act in a self-protective way.
On the negative side, this overlay can create a slight paranoia if either of you fear close and deep connections. The good thing with this overlay is that you share an ability to communicate subliminally with each other. The intuition between you is strong.