Abstract: A system for expense calculation, accrual, allocation, and reconciliation, including an expense calculation module configured to receive transaction data relating to a transaction and to apply at least one charge rule to the transaction data to calculate expense data detailing the expenses expected to be charged in association with the transaction; an accounting control module configured to receive the expense data as an input and to apply at least one accounting rule to the expense data to create enhanced data relating to the transaction; and an invoice reconciliation module configured to receive as inputs the expense data as well as invoice data related to the transaction, and to determine whether the invoice data matches the expense data for the transaction.