The different illustrative embodiments provide a method for managing user identifiers presented in accordance with an illustrative embodiment. In an illustrative embodiment, a determination is made whether the new user identifier matches an existing user identifier according to a policy for a minimum degree of character variation between the new user identifier and the existing user identifier responsive to receiving a request to store a new user identifier. The request to store the new user identifier is rejected responsive to a determination that the new user identifier matches the existing user identifier according to the policy. The request is approved responsive to an absence of a determination that the new user identifier matches the existing user identifier according to the policy.