We are transitioning a small organization to CiviCRM 4.5, with about 2000 total contacts and about 150 memberships. The contacts imported without any problem, but when we went to import the memberships, we found that CiviCRM required either an e-mail address or an external ID.

About half of the members do not have an email address, and since the old membership system was a combination of Excel files and offline physical media, they have no unique membership numbers or other identifiers. All of the firstname+lastname combinations are unique, so we thought that should be sufficient, and we have the deduplication rule set to that effect elsewhere, but it seems to be inadequate for membership imports.

We don't want to be in the business of creating dummy email addresses, so it seems we must manually assign an external ID to the old contact list and the membership list, then reimport both in turn. But is there an easier workaround— some way to use Firstname+Lastname as the unique identifier? Or is there another "best practice" we could adopt here?