An affinity group is a group consisting of persons who assemble together with a commonality of purpose or engaging in a common economic activity.
In Insurance parlance Non-employer-employee groups like employee welfare associations, borrowers of a bank, professional associations or societies may also be treated as affinity groups provided the president/ secretary/ manager/ group organizer in his capacity as organizer of the group has an authority from majority of the members of the group to arrange insurance on their behalf.