Once an Account is enabled as a partner, it appears in reports and list views that are filtered on the isPartner field. Additionally, partner users can be created from contacts associated with this Account.
Selecting a partner on an account or opportunity automatically creates a reverse partner relationship so that both accounts list the other as a partner. The role you select is applied to the partner account; in the current account, the reverse role is applied.
Removing a partner from an opportunity or account removes the partner’s relationship with the opportunity or account, but does not delete the partner account.
If you change the account for an opportunity that has partners, all partners are deleted from the Partners related list.
Partner accounts can’t be deleted, but can be disabled.
Disabling an account with external users permanently disables all external users associated with the account and removes them from all communities, groups, teams, permission sets and sharing rules with which they are associated. Also, roles and groups associated with the account are permanently deleted and not moved to the Recycle Bin.