Link AWS accounts for Collection of consolidated billing data
Some large organizations create separate AWS accounts for different cost centers and then link these accounts to a Payer Account. In this case, the billing records for all of these accounts are accumulated in the billing records for the Payer Account. If you want to have a single AWS IAM user to collect these billing records and all other information about EC2 and S3 buckets, you will need to grant the user cross-account API access. By linking accounts, you establish a trust relationship between the accounts.
Ensure that the account used in AWS policy has the user access privilege to perform call to the API