As evidenced in the previous sections, there are many different ways to establish security relationships between accounts. AWS customers with multiple AWS accounts often leverage consolidated billing, and it can be tempting to use the master billing account for security activities such as centralized IAM administration or storing log files for member accounts. However, most customers eventually choose to create separate security account hierarchies. When determining the appropriate account structure for your security needs, AWS recommends taking an iterative approach because AWS customers rarely require every available option immediately. Some companies might find that a single hierarchical account structure is slow to form, or that separate diagrams are necessary to adequately describe different account relationships. In fact, when separating different account-related concerns (such as billing, security log processing, compliance monitoring, or shared IT services) across multiple accounts, multiple hierarchies are often more desirable than a single hierarchy. Whatever the structure, ensure that account relationships are well documented and well understood. The following examples demonstrate how the various structures listed previously can be combined for Information Security or central IT purposes, and are only a few of the many ways a company can structure and compartmentalize security-related functions.