[34] Contract balances

Contract assets stood at €278.1 million (December 31, 2023: €403.3 million); most of this amount, €263.6 million (December 31, 2023: €390.6 million), was attributable to goods and services provided in the project business that have not yet been billed.

Of the contract liabilities, €566.1 million was attributable to project business contracts with a net debit balance due to customers (December 31, 2023: €582.7 million) and €212.5 million to prepayments received from customers (December 31, 2023: €190.6 million). The revenue recognized in the reporting period that was included in the contract liability balance at the beginning of the period amounted to €665.4 million (2023: €721.1 million).