How do I invite my spouse to counselling without them feeling accused of being the cause of the problem?

Frame counselling as a shared effort to improve the relationship, not as a correction of them. Avoid words that point the finger, as if they are the only one who needs to change; instead try ‘I want us to be happier, and I think someone could help us’. Acknowledge your own part in the problem so they do not feel attacked alone. Choose a calm time, not during a fight, to bring it up. Suggest trying it just once first without a long commitment. If they are still unsure, offer to choose the counsellor together so they feel respected. A tone that invites, not accuses, opens more doors. See communication & emotions.