(58)In accordance with Article 19(4) of Directive 2004/39/EC, a firm is required to assess the suitability of investment services and financial instruments to a client only when it is providing investment advice or portfolio management to that client. In the case of other investment services, the firm is required by Article 19(5) of that Directive to assess the appropriateness of an investment service or product for a client, and then only if the product is not offered on an execution-only basis under Article 19(6) of that Directive (which applies to non-complex products).