What is a membership ledger?

A membership ledger is one of the records that an LLC should always maintain and keep up to date. Similar to a share ledger for a corporation, this is simply a registry listing and identifying each of the owning members, indicating their percentage of ownership, and including any information relating to the sale or transfer of ownership interests (that is, if a member sold or transferred his/her membership units, the membership ledger should indicate where those units went).