I work with couples in Crouch End and Peterborough. Seeing a counsellor as a couple gives you both a chance to say things with an independent person present. This provides another perspective that can help you to see things more clearly, and potentially move forward.
Similarly, any two people can come to counselling together. It could be friends or family members, who would like the opportunity to talk things through with another person there, who is trained in listening.
With couples, I offer longer sessions of 1 hour and 20 minutes. This gives you both plenty of time to have your say, and means a change of perspective is more likely.