Our members are all organisations (schools and colleges). Payment is taken outside of Civi after sending an invoice. We're not currently using Contributions. We're looking at a big project to automate/improve our reporting. I'm interested in using a contribution page internally to record payment, most likely using a price set to count how many of certain options they have purchased either with their membership or separately afterwards.
It is important that we only create memberships on existing organisations, but the help for selecting an "On Behalf Of" profile says "The profile must include Organization Name and Email Address". Is there a way of restricting the selection of organisations to existing only, and preferably within certain subtypes or a certain group?