To gain competitive advantage in Europe, it is vital for small and medium sized enterprises (SMEs) to utilise knowledge efficiently and to tap into full innovation potential. Reporting those intangible assets systematically to customers, partners, investors or creditors has become a critical success factor. Thus, managing "intellectual capital" (IC) becomes increasingly important for future‑oriented organisations. Conventional balance sheets and controlling instruments are not sufficient any more, because intangible assets are not considered. The collective research project "Intellectual Capital Statement â€” Made in Europe" considers national experiences and the current state‑of‑the‑art on measuring IC and will establish a European ICS guideline for implementing Intellectual Capital Statements (ICS). The ICS is an instrument to assess, develop and report an organisation's IC, to monitor critical success factors systematically, and to support strategic management decisions (cf. Mertins, Will 2007).For customers, investors and especially creditors, after receiving an ICS, one of the first things that usually comes into their mind is: Is this information "reliable"? To ensure a high quality level of ICS and to be accepted by, for instance, the financial market, it is important to have a neutral third party who certifies the reliability of the document. Learning from the experiences of ISO 9001 certification, assessment for the European Excellence Award and of financial audits, an ICS audit methodology has been developed. The ICS audit verifies the conformity with the European guideline respective ICS implementation process and the completeness of the ICS content. Furthermore, it will check whether the content is plausible, verifiable and representative for the company. To ensure sustainability, the auditor will get a picture of whether the ICS content is communicated and the stated actions for improvements are in progress or already realised. The main focus of this paper is to demonstrate how to ensure the quality and reliability of IC reporting and how to promote the sustainable realisation of actions by ICS audits.