[ESMA 35-43-349 MiFID II Q&As Investor protection Ch. 9, question 11]

When the investment firm is not able to obtain the relevant data from the manufacturer, the investment firm should first assess whether it can provide its clients with adequate information on the total costs and charges of the financial instrument and the investment service. ESMA would expect investment firms to base these calculations on the methodology prescribed in the PRIIPs RTS. It is essential that the investment firm has assured itself that it can make a reasonable and sufficiently accurate estimate of the total costs of the financial instrument. If this is the case, an investment firm may use this estimate to calculate the ex-ante and ex-post figures on costs and charges.