Prior literature points to the importance of party power and ideology for interest group-party contacts in the legislative arena. But interest groups do not often have ideologies – they are typically active in a small number of policy domains and there may be different parties that share more similar preferences across different policy areas. Therefore, we examine whether and how party power and proximity in policy preferences predict the existence of party-interest group ‘lobby routines’ in specific policy domains, using a novel survey of representative samples of interest groups in seven long-established democracies. We find that groups often form routines with different parties in different policy areas and that preference proximity on relevant policy dimensions is positively associated with having such area-specific lobby routines. However, the results also suggest that powerful parties are more likely allies and that the effect of policy proximity on routines is positively conditioned by power.