This topic lists the limitations of RAM, such as the maximum number of RAM users and the maximum number of RAM user groups.

Item Limit
Maximum number of RAM users that can be created in an Alibaba Cloud account 1,000
Maximum number of characters that a username can contain 64
Maximum number of RAM user groups that a RAM user can join 5
Maximum number of access keys that a RAM user can create 2
Maximum number of multi-factor authentication (MFA) devices that can be attached to a RAM user 1
Maximum number of system policies that can be attached to a RAM user 20
Maximum number of custom policies that can be attached to a RAM user 5
Maximum number of RAM user groups that can be created in an Alibaba Cloud account 50
Maximum number of characters that a RAM user group name can contain 64
Maximum number of system policies that can be attached to a RAM user group 20
Maximum number of custom policies that can be attached to a RAM user group 5
Maximum number of RAM roles that can be created in an Alibaba Cloud account 100
Maximum number of characters that a RAM role name can contain 64
Maximum number of system policies that can be attached to a RAM role 20
Maximum number of custom policies that can be attached to a RAM role 5
Maximum number of characters that an Alibaba Cloud account alias can contain 64
Note The Alibaba Cloud account alias must be 3 to 64 characters in length.
Maximum number of characters that a policy name can contain 128
Maximum number of MFA devices that can be created in an Alibaba Cloud account 1,000
Maximum number of custom policies that can be created in an Alibaba Cloud account 200
Maximum number of characters that a custom policy can contain 2,048
Maximum number of versions that a custom policy can have 5
Maximum number of identity providers (IdPs) that can be created in an Alibaba Cloud account 100
Maximum number of IdP descriptors that an IdP metadata file can contain 1
Maximum number of certificates that an IdP descriptor in an IdP metadata file can contain 2