A user-promotion process allows a service provider to grant the security roles associated with a target user account to a requester by obtaining approvals from a quorum of approving users. The quorum requirements and the identity of the approving users may be established by the target user or an account manager. Upon receiving, from a promotion candidate, a request to assume security roles of a target user, the service provider identifies the approving users from the target user's account record. Approvals are requested from the approving users, and if a quorum of approvals is received by the service provider, the promotion candidate is allowed to assume the roles of the target user. If a quorum of approvals is not received, then substitute approving users may be identified based at least in part on those approving users that did not respond to the approval request.